Exhibit 31.2

I,  David  W.  Whitwell,  certify  that:

1.     I  have  reviewed  this  quarterly  report  on  Form 10-Q of Clean Diesel
Technologies  Inc.:

2.     Based  on my knowledge, this report does not contain any untrue statement
of  a  material  fact  or  omit  to  state a material fact necessary to make the
statements  made, in light of the circumstances under which such statements were
made,  not  misleading  with  respect  to  the  period  covered  by this report;

3.     Based  on  my  knowledge,  the  financial statements, and other financial
information included in this report, fairly present in all material respects the
financial  condition,  results of operations and cash flows of the registrant as
of,  and  for,  the  periods  presented  in  this  report;

4.     The  registrant's  other  certifying officer(s) and I are responsible for
establishing  and  maintaining disclosure controls and procedures (as defined in
Exchange  Act  Rules  13a-15  (e)  and  15d-15  (e))  and  internal control over
financial reporting (as defined in Exchange Act Rules 13a-15 (f) and 15d-15 (f))
for  the  registrant  and  have:
          a)   Designed  such  disclosure  controls  and  procedures  or  caused
               such  disclosure controls and procedures to be designed under our
               supervision  to  ensure that material information relating to the
               registrant,  including  its  consolidated  subsidiaries,  is made
               known  to us by others within those entities, particularly during
               the  period  in  which  this  report  is  being  prepared;  and
          b)   designed  such  internal  control  over  financial  reporting, or
               caused  such  internal  control  over  financial  reporting to be
               designed  under  our supervision, to provide reasonable assurance
               regarding  the  reliability  of  financial  reporting  and  the
               preparation  of  financial  statements  for  external purposes in
               accordance  with  generally  accepted  accounting  principles;
          c)   evaluated  the  effectiveness  of  the  registrant's  disclosure
               controls  and  procedures  and  presented  in  this  report  our
               conclusions  about  the  effectiveness of the disclosure controls
               and  procedures,  as  of  the  end  of the period covered by this
               report  based  on  such  evaluation;  and
          d)   disclosed  in  this  report  any  change  in  the  registrant's
               internal  control  over  financial reporting that occurred during
               the  registrant's  most  recent  fiscal quarter (the registrant's
               fourth  fiscal  quarter in the case of an annual report) that has
               materially  affected,  or  is  reasonably  likely  to  materially
               affect,  the  registrant's  internal  control  over  financial
               reporting;  and

5.     The  registrant's other certifying officer(s) and I have disclosed, based
on  our  most recent evaluation of internal control over financial reporting, to
the  registrant's  auditors and the audit committee of the registrant's board of
directors  (or  persons  performing  the  equivalent  functions):
          a)   All significant  deficiencies  and  material  weaknesses  in  the
               design  or  operation  of  internal  controls  over  financial
               reporting,  which  are  reasonably likely to adversely affect the
               registrant's  ability  to  record,  process, summarize and report
               financial  information;  and
          b)   Any fraud,  whether  or  not  material,  that involves management
               or  other  employees  who  have  a  significant  role  in  the
               registrant's  internal  control  over  financial  reporting;

Date:  May  11,  2006            By:  /s/David  W. Whitwell
                                      -----------------------------------
                                      David  W.  Whitwell
                                      Chief  Financial  Officer,
                                      Senior Vice President and Treasurer