<PAGE>   1
                                                                 EXHIBIT 10.22.3



                               GUARANTY AGREEMENT

         THIS GUARANTY AGREEMENT (as may be amended or otherwise modified from
time to time, this "Guaranty") dated as of November 29, 2000, is from Probex
Corp., a Delaware corporation ("Guarantor"), and is to and for the benefit of
the Noteholders referred to hereinafter and Wilmington Trust Company, as
Collateral Agent for the Noteholders (in such capacity the "Collateral Agent").


                                   WITNESSETH:

         A. Probex Fluids Recovery, Inc., a Delaware corporation (the
"Company"), the various investors (collectively, the "Noteholders") as are or
may from time to time become parties thereto and Guarantor have entered into a
Note Purchase Agreement of even date herewith (herein, as the same may be
amended, modified, supplemented, extended, rearranged, restated, or waived from
time to time, called the "Note Purchase Agreement"), pursuant to which, upon the
terms and conditions therein set forth, the Noteholders have agreed to advance
funds to the Company, which funds are evidenced by the 7% Senior Secured
Convertible Notes of the Company of even date herewith, in the aggregate
original principal amount of $12,500,000, payable to the Noteholders,
respectively (herein, as such convertible promissory notes are amended,
extended, modified, rearranged and/or supplemented, from time to time together
with any promissory notes given in extension, replacement, rearrangement,
modification and/or substitution thereof or therefor, collectively called the
"Notes"). Capitalized terms used herein without definition shall have the
meanings assigned in the Note Purchase Agreement.

         B. As a condition precedent to the execution and delivery of the Note
Purchase Agreement, the Guarantor is required to execute and deliver this
Guaranty.

         C. The Guarantor has duly authorized the execution, delivery and
performance of this Guaranty.

         D. It is in the best interests of the Guarantor to execute this
Guaranty inasmuch as the Guarantor will derive substantial direct and indirect
benefits from the funds to be advanced to Company pursuant to the Note Purchase
Agreement.

         NOW THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the Guarantor agrees, for the
benefit of the Collateral Agent and each other Noteholder, as follows:


                                       1
<PAGE>   2

                                   ARTICLE I.

                                    Guaranty

1.1. Guaranty. For value received, and in consideration of any loan or other
financial accommodation, heretofore or hereafter at any time made or granted to
the Company by the Noteholders, the Guarantor hereby unconditionally guarantees
the full and prompt payment when due, whether by acceleration or otherwise, and
at all times thereafter, of all obligations of the Company to the Collateral
Agent and each Noteholder and their successors and assigns, howsoever created,
arising or evidenced, whether direct or indirect, primary or secondary, absolute
or contingent, joint or several, or now or hereafter existing or due or to
become due, including, without limitation, all such amounts which would become
due but for the operation of the automatic stay under Section 362(a) of the
United States Bankruptcy Code, 11 U.S.C. Section 362(a), and the operation of
Sections 502(b) and 506(b) of such Bankruptcy Code, 11 U.S.C. Section 502(b) and
Section 506(b), under and in connection with the Note Purchase Agreement,
including, without limitation under (a) the Notes, (b) the Note Purchase
Agreement and (c) the Security Agreement (all such obligations being hereinafter
collectively called the "Liabilities"), and the Guarantor further agrees to pay
all expenses (including reasonable attorneys' fees and legal expenses) paid or
incurred by the Collateral Agent and any other Noteholder in endeavoring to
collect the Liabilities, or any part thereof, and in enforcing this Guaranty.
Anything herein contained to the contrary notwithstanding, the amount of this
Guaranty, however, shall not exceed the maximum amount which the Guarantor can
pay under this Guaranty without having such payment set aside as a fraudulent
transfer or conveyance or similar action under such Bankruptcy Code or any
applicable state law. The term Liabilities shall include any future advances by
the Noteholders (whether in the form of debt or equity) to or for the benefit of
the Borrower, regardless of whether before or after the Noteholders become the
owner of any or all of the stock in the Borrower. This Guaranty is a direct
obligation of Guarantor to make the Investors whole on the investment evidenced
by the Notes and the Note Purchase Agreement (including interest and other
amounts payable under the Note Purchase Agreement).

1.2. Bankruptcy. The Guarantor hereby agrees that, in the event of the
dissolution or insolvency of the Company or the Guarantor, or the inability or
failure of the Company or the Guarantor to pay their respective debts as they
become due, or an assignment by the Company or the Guarantor for the benefit of
creditors, or the commencement of any case or proceeding in respect of the
Company or the Guarantor under any bankruptcy, insolvency or similar laws, and
if such event shall occur at a time when any of the Liabilities may not then be
due and payable, the Guarantor will pay to the Noteholders forthwith the full
amount which would be payable hereunder by the Guarantor as if all Liabilities
were then due and payable.

1.3. Setoff. In addition to any rights now or hereafter granted under applicable
law and not by way of limitation of any such rights, upon the occurrence of, and
throughout the continuance of, any Event of Default under the Note Purchase
Agreement (an "Event of Default"), the Collateral Agent and each Noteholder and
each subsequent holder of any of the Notes is hereby authorized by the Guarantor
without notice to the Company,


                                       2
<PAGE>   3

the Guarantor or any other Person, any such notice being hereby expressly
waived, to set off and to appropriate and to apply any and all indebtedness at
any time held or owing by the Collateral Agent or any Noteholder, that
Noteholder or that subsequent holder to or for the credit or the account of the
Guarantor, whether or not matured, against and on account of the obligations and
liabilities of the Company or the Guarantor to the Collateral Agent, such
Noteholder or such subsequent holder under the Note Purchase Agreement,
including, but not limited to, all claims of any nature or description arising
out of or connected with the Financing Documents (as such term is defined in the
Intercreditor Agreement) irrespective of whether or not (a) the Collateral
Agent, such Noteholder or such subsequent holder shall have made any demand
hereunder, or (b) the liabilities or any other amounts due hereunder shall have
become due and payable and although said obligations and liabilities, or any of
them, may be contingent or unmatured.

1.4. Guaranty Absolute, etc. This Guaranty shall in all respects be a
continuing, absolute and unconditional Guaranty, and shall remain in full force
and effect (notwithstanding, without limitation, the dissolution of the Company
or the Guarantor or that at any time or from time to time all Liabilities may
have been paid in full), until all Liabilities (including any renewals,
extensions and/or rearrangements of any thereof), all interest thereon and all
reasonable expenses (including reasonable attorneys' fees and legal expenses)
paid or incurred by the Collateral Agent and the other Noteholders in
endeavoring to collect the Liabilities and in enforcing this Guaranty shall have
been finally paid in full and the Commitments have been permanently terminated.

1.5. Reinstatement. The Guarantor further agrees that, if at any time all or any
part of any payment theretofore applied by the Collateral Agent or any
Noteholder to any of the Liabilities is or must be rescinded or returned by the
Collateral Agent or any Noteholder for any reason whatsoever (including, without
limitation, the insolvency, bankruptcy or reorganization of the Company), such
Liabilities shall, for the purposes of this Guaranty, to the extent that such
payment is or must be rescinded or returned, be deemed to have continued in
existence, notwithstanding such application by the Collateral Agent or any
Noteholder, and this Guaranty shall continue to be effective or be reinstated,
as the case may be, as to such Liabilities, all as though such application by
the Collateral Agent or any Noteholder had not been made.

1.6. Rights of the Collateral Agent and Noteholders. The Collateral Agent or any
Noteholder may, from time to time, at its sole discretion and without notice to
the Guarantor, take any or all of the following actions:

         (a) retain or obtain a lien upon or a security interest in any property
of the Company to secure any of the Liabilities or any obligation hereunder;

         (b) retain or obtain the primary or secondary obligation of any obligor
or obligors, in addition to the Guarantor, with respect to any of the
Liabilities;

         (c) extend or renew for one or more periods (whether or not longer than
the original period), alter or exchange any of the Liabilities, or release or
compromise any


                                       4
<PAGE>   4

obligation of any Guarantor hereunder or any obligation of any nature of any
other obligor with respect to any of the Liabilities;

         (d) extend or renew for one or more periods (whether or not longer than
the original period) or release, compromise, alter or exchange any obligations
of any nature of any obligor with respect to any such property securing any of
the Liabilities; or

         (e) resort to Guarantor for payment of any of the Liabilities, whether
or not the Collateral Agent or the Noteholders shall have proceeded against any
other obligor primarily or secondarily obligated with respect to any of the
Liabilities (all of the actions referred to in this clause being hereby
expressly waived by the Guarantor).

1.7. Application of Payments. Any amounts received by the Collateral Agent or
any Noteholder from whatsoever source on account of the Liabilities may be
applied by it toward the payment of such of the Liabilities, and in such order
of application, as the Collateral Agent or any Noteholder may from time to time
elect, in each case consistent with the terms and provisions of the Note
Purchase Agreement and the Intercreditor Agreement.

1.8. Waiver.  (a)      The Guarantor hereby expressly waives:

                  (i) notice of the acceptance by the Collateral Agent or any
Noteholder of this Guaranty;

                  (ii) notice of the existence or creation or non-payment of all
or any of the Liabilities;

                  (iii) presentment for payment, demand, protest, notice of
intent to accelerate, notice of acceleration, notice of dishonor and all other
notices whatsoever;

                  (iv) all diligence in collection or protection of or
realization upon the Liabilities or any portion thereof, any obligation
hereunder, or any security for or guaranty of any of the foregoing; and

                  (v) any rights under, or any requirements imposed by, Chapter
34 of the Texas Business and Commerce Code (or other applicable laws giving
rights or defenses to sureties), as amended, and any rights or requirements that
the Collateral Agent or any Noteholder first enforce any rights or remedies
against the Borrower or any other guarantor or against any collateral for any of
Liabilities.

         (b) No delay on the part of the Collateral Agent or any Noteholder in
the exercise of any right or remedy shall operate as a waiver thereof, and no
single or partial exercise by the Collateral Agent or any Noteholder of any
right or remedy shall preclude other or further exercise thereof or the exercise
of any other right or remedy; nor shall any modification or waiver of any of the
provisions of this Guaranty be binding upon the Collateral Agent or any
Noteholder except as expressly set forth in a writing duly signed and delivered
on behalf of the Collateral Agent or such Noteholder. No action of the
Collateral Agent or any Noteholder permitted hereunder shall in any way affect
or impair



                                       4
<PAGE>   5

the rights of the Collateral Agent or any Noteholder and the obligations of the
Guarantor under this Guaranty. The obligations of the Guarantor under this
Guaranty shall be joint, several, absolute and unconditional irrespective of any
circumstance whatsoever which might constitute a legal or equitable discharge or
defense of Guarantor. The Guarantor hereby acknowledges that there are no
conditions to the effectiveness of this Guaranty.

1.9. Subrogation. No payment made by or for the account of the Guarantor
pursuant to this Guaranty shall entitle Guarantor by subrogation or otherwise to
demand or receive any payments by the Company or from or out of any properties
of the Company until the Liabilities shall have been paid in full. The Guarantor
shall not exercise any right or remedy against the Company or any properties of
the Company by reason of any performance by the Guarantor of this Guaranty until
the Liabilities shall have been paid in full.

1.10. Subordination. The Guarantor hereby subordinates its rights to payment
from the Borrower of any obligations, howsoever created, arising or evidenced,
whether direct or indirect, absolute or contingent, now or hereafter existing or
due or to become due (collectively, the "Guarantor Liabilities"), to the
Liabilities of the Borrower to the Collateral Agent and the Noteholders, and no
payments or other distributions whatsoever in respect of any such Guarantor
Liabilities shall be made, nor shall any property or assets of the Company be
applied to the purchase, acquisition or retirement of any such Guarantor
Liabilities; provided that payments on such Guarantor Liabilities may be made at
any time no Event of Default or event, which with the passage of time or notice,
or both, may become an Event of Default shall have occurred and be continuing.
Any payments received by the Guarantor in respect of any such Guarantor
Liabilities owing to it other than as expressly provided herein shall be held in
trust for the Collateral Agent and the Noteholders.

1.11. Excess Liabilities. The creation or existence from time to time of
Liabilities in excess of the amount to which the right of recovery under this
Guaranty is limited, if any, is hereby authorized, without notice to the
Guarantor, and shall in no way affect or impair the rights of the Noteholders
and the obligations of the Guarantor under this Guaranty.

1.12. Successors. Transferees and Assigns. The Collateral Agent and each
Noteholder may, from time to time, without notice to the Guarantor, assign or
transfer any or all of the Liabilities or any interest therein in accordance
with the terms of the Note Purchase Agreement; and, notwithstanding any such
assignment or transfer or any subsequent assignment or transfer thereof, such
Liabilities shall be and remain Liabilities for the purposes of this Guaranty,
and each and every immediate and successive assignee or transferee of any of the
Liabilities or of any interest therein shall, to the extent of the interest of
such assignee or transferee in the Liabilities, be entitled to the benefits of
this Guaranty to the same extent as if such assignee or transferee were the
transferring Noteholder; provided, however, that, unless the transferring
Noteholder shall otherwise consent in writing, the transferring Noteholder shall
have an unimpaired right, prior and superior to that of any such assignee or
transferee, to enforce this Guaranty, for the benefit of the transferring
Noteholder as to those of the Liabilities which the transferring Noteholder has
not assigned or transferred.



                                       5
<PAGE>   6

                                  ARTICLE II.

                         Representations And Warranties

2.1. Independent Means of Obtaining Information. The Guarantor hereby represents
and warrants to the Collateral Agent and each Noteholder that it now has and
will continue to have independent means of obtaining information concerning the
affairs, operations, financial condition, business and prospects of the Company.

2.2. Authorization; No Conflict. The Guarantor hereby further represents and
warrants to the Collateral Agent and each Noteholder that

         (a) the execution and delivery of this Guaranty, and the performance by
the Guarantor of its obligations hereunder, are within Guarantor's corporate
powers and have been duly authorized by all necessary corporate action on the
part of Guarantor; and

         (b) this Guaranty has been duly executed and delivered on behalf of
Guarantor and is the legal, valid and binding obligation of Guarantor,
enforceable in accordance with its terms subject as to enforcement only to
bankruptcy, insolvency, reorganization, moratorium or other similar laws
affecting the enforcement of creditors' rights generally and equitable
principles relating to or limiting creditors' rights generally, the making and
performance of which do not and will not contravene or conflict with the
articles or certificate of incorporation and by-laws or other corporate
governance documents of Guarantor or violate or constitute a default under any
law, any presently existing requirement or restriction imposed by any judicial,
arbitral or governmental instrumentality or any agreement, instrument or
indenture by which the Guarantor is bound.

2.3. Validity and Binding Nature. This Guaranty shall be binding upon the
Guarantor, and upon the successors and assigns of the Guarantor, and shall
include any successor or successors, whether immediate or remote, to such
entity; provided, however, that the Guarantor may not assign any of its
obligations hereunder without the prior written consent of the Collateral Agent
and the Noteholders.

                                  ARTICLE III.

                            Miscellaneous Provisions

3.1. Governing Law; Submission to Jurisdiction; Waiver of Jury Trial. This
Guaranty, and the rights and duties of the parties hereto, shall be construed in
accordance with and governed by the internal laws of the State of Texas. The
Guarantor hereby submits to the nonexclusive jurisdiction of the United States
District Court for the Northern District of Texas and of any Texas state court
sitting in Dallas, Texas for purposes of all legal proceedings arising out of or
relating to this Guaranty or the transactions contemplated hereby. Each party
hereto irrevocably waives, to the fullest extent permitted by law, any objection
it may now or hereafter have to the laying of the venue of any such proceeding
brought in such a court




                                       6
<PAGE>   7

and any claim that any such proceeding brought in such a court has been brought
in an inconvenient forum. EACH PARTY TO THIS GUARANTY HEREBY IRREVOCABLY WAIVES
ALL RIGHT TO A TRIAL BY JURY IN ANY ACTION, PROCEEDING OR COUNTERCLAIM ARISING
OUT OF OR RELATING TO THIS GUARANTY OR THE TRANSACTIONS CONTEMPLATED HEREBY.
NOTWITHSTANDING ANYTHING TO THE CONTRARY IN THIS SECTION, THE RIGHTS, DUTIES,
IMMUNITIES, INDEMNITIES AND STANDARD OF CARE OF WILMINGTON TRUST COMPANY,
INDIVIDUALLY, AND AS COLLATERAL AGENT SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF DELAWARE.

3.2. Severability. Wherever possible, each provision of this Guaranty shall be
interpreted in such manner as to be effective and valid under applicable laws,
but if any provision of this Guaranty shall be prohibited by or invalid under
such laws, such provision shall be ineffective to the extent of such prohibition
or invalidity, without invalidating the remainder of such provision or the
remaining provisions of this Guaranty.

3.3. Notices. Except as otherwise specified herein, all notices under this
Guaranty shall be in writing (including cable, telecopy or telex) and shall be
given to the Guarantor at the address, telecopier number or telex number set
forth on the signature page hereof or such other address, telecopier number or
telex number as Guarantor may hereafter specify by notice to the Collateral
Agent, given by courier, by United States certified or registered mail, by
telegram or by other telecommunication device capable of creating a written
record of such notice and its receipt. Each such notice, request or other
communication shall be effective (i) if given by telecopier, when such telecopy
is transmitted to the telecopier number specified in this Section on the
signature pages hereof and a confirmation of receipt of such telecopy has been
received by the sender, (ii) if given by telex, when such telex is transmitted
to the telex number specified on the signature pages hereof and the answerback
is received by sender, (iii) if given by courier, when delivered, (iv) if given
by mail, five (5) days after such communication is deposited in the mail,
certified or registered with return receipt requested, or (v) if given by any
other means, when delivered at the addresses specified on the signature page
hereof. Notwithstanding anything to the contrary in this Section 3.3, any notice
given to the Collateral Agent shall be effective only upon receipt by the
Collateral Agent.

                          [Signatures on the next page]


                                       7
<PAGE>   8




         IN WITNESS WHEREOF, the Guarantor has caused this Guaranty to be duly
executed and delivered by its duly authorized officer as of the date first above
written.


                               GUARANTOR:

                               Probex Corp., a Delaware corporation



                               By: /s/ BRUCE A. HALL
                                  ---------------------------------------------
                               Name: Bruce A. Hall
                                    -------------------------------------------
                               Title: Senior Vice President & Chief Financial
                                      Officer
                                      -----------------------------------------
                               Address:   13355 Noel Road, Suite 1200
                                          Dallas, Texas 75240
                               Attention: Bruce Hall
                                          Telecopy No. 972/980-8545


                                       8
<PAGE>   9




                              COLLATERAL AGENT:

                              WILMINGTON TRUST COMPANY



                              By: /s/ JOSEPH B. FEIL
                                 ---------------------------------------------
                              Name: Joseph B. Feil
                                   -------------------------------------------
                              Title: Senior Financial Services Officer
                                    ------------------------------------------

                              Address:   Wilmington Trust Company
                                         1100 North Market Street
                                         Rodney Square North
                                         Wilmington, DE 19890-0001
                              Attention: Corporate Trust Administration - Probex



                                       9