The mechanics thought it was running lean just by hearing and smelling the engine. I replaced the O2 sensors on Friday and I can see a little difference but not much.
There's an article on the same problem I'm having in the newest MM and FF magazine called Idle Surge. The stone pony project car has basically the same mods as me except for different brands and it was having the same problem until they changed their 94-95 computer to a 93 computer. I'm thinking of doing that now but it's about $600.00 more than what I have now after spending all my money on the upgrades. I was going to try the custom chip next. I'm not sure how radical is considered radical for a cam but my specs are as follows:
lift at valve .500/.510
advertised duraton 284/292
duration at .050 tappet lift 218/226
Quote:
Originally posted by jimberg:
O2 sensors with 94000 miles on them should be changed. Period. Your car will run its best when the feedback the computer gets is most accurate. They could have been damaged when you did the exhaust or when you did the heads. Who knows. Just consider it money well spent no matter what the outcome.
You should probably hook up a fuel pressure gauge to make sure that your FPR hasn't gone south on you. Make sure you have 37-40 psi and that it goes down if you apply vacuum to the vacuum port. You may also want to perform a leak down test.
You should never need a custom tuned chip to run normally (maybe to smooth out an idle with a radical cam or something). They come in handy when you want to run leaner or richer than stock, or with a different timing advance curve.
Did the mechanics get the codes from the computer or did they just put a dab of oil on their finger and taste for problems? 
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