It is a 1 piece seal and according the current Chilton guide it takes a Pro 5.8 hours to do the job. Save yourself some grief and have it done by an expert. Service engine soon light comes on. Replaced EGR, light still comes on with same code. Replace control module.
Light still comes on with same code, but very infrequently.
There are 2 separate modules. If you have not replaced EGR module start there. If you have replaced the EGR module, you have a wiring problem. I've talked to several people about the advisability of such a modification, and have been thoroughly confused about the facts. One person has told me that a set of cast iron manifolds will work just fine.