Well...so far so good. In the past everytime the OBD was reset the CE light would come back within 5 miles; I'm now at 15 with no light. After doing some exploratory work, here's a pic of what I found:
Holy plugged passages batman! These are the fabled 3 EGR passages that lead directly to the EGR valve, and obviously mine were completely plugged up. In fact it was so plugged up that I didn't even recognize the passages until I sprayed some Berrymans into the EGR passage behind the EGR valve itself & it started to ooze out the middle TB passage (the other two were 100% blocked.) And I also wouldn't have found all this buildup if I hadn't carefully removed the TB gasket. I spent the better part of an hour cleaning this up as well as digging out the rest of the passageway up into the UIM as best I could with Q-tips.
I also removed the EGR valve itself, clean/inspected it as well as most of the surrounding lines & the main EGR tube, and it all looked pretty good. Apparently when my local shop said "the EGR system looks really clean" they meant the actual valve, but in all honesty I would have never noticed these three passages unless I'd have either A. sprayed a bunch of carb cleaner into the main EGR passage like I did, or B. removed the TB gasket.
In any case, the CE has yet to return...hopefully this took care of the problem. I've also noticed that the bad sulfur smell I had under moderate/hard acceleration is gone too, guess my cats weren't bad after all
If the CE light comes back on I'll post up here, otherwise I'd say this problem is CLOSEFILE. And one last thing...if you do this little bit of maintainece, make SURE you get all the hoses hooked back up. A 2.5 will make some horrendous sucking noises and run like stale poop if you forget to hook up the PCV system
91 SHO plus black/black, work in progress
