Need help on emissions getting to much fuel

gonemad87

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Joined
Jan 13, 2011
Any help or advice we be great I attached pic of pre smog seem I passed most said it was getting to much fuel kinda stuck where to start first
 

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87 we4 78k original miles motor n trans is stock minus usual bolt ons.fuel pressure regulator,42lbs injectors with turbo tweak 91 pump gas chip. Hot wire kit I do believe cat is original but was told its fine
 
I was told my cat was fine too and it was gutted. TT chip has egr disabled unless its a smog chip.
 
Ok Ima do the standard tune up and change plugs and adjust fuel regulator change 02 sensor I believe it is the regular TT chip will it not pass if EGR is disabled?? I'm guessing I should throw a new cat on it also
 
EGR mainly affects NOx. Your NOx is passing, so you might be inclined to think you don't need the EGR turned on. But wait a sec, high NOx comes from running high compression, or high temp motors or lean-ness. You've got a low compression, rich running motor at the moment, and if you have a 160tstat, a cold running motor as well. That will almost guarantee low NOx even without EGR or a 3-way cat. As you get your motor better tuned to pass HC and CO your NOx will rise, in which case having a functioning EGR will become more important.

Where to start? You'll need SM to check a few things, without one you could take a gander at MAF (even a new replacement might be flaky), o2 sensor (cheap), stuck injector - a fp gauge showing drop in pressure could show that and/or just look at the plugs, bad injector signal from ecm - rent a noid light from your auto store. And the big ticket item - the cat. Host of other things, weak spark, lean miss, etc., but some sort of monitoring device will help greatly. Good luck!
 
If HC is high, I'd doubt that the cat is bad. It's more likely to be a vacuum leak than anything else. I'd recommend a TT emissions chip and a 180 thermostat. If he has a TT performance chip, that's probably the reason it's running fat. He also has the 42lb injectors, and those are notorious for running fat anyway.
 
If HC is high, I'd doubt that the cat is bad.
My HC were five times higher with a gutted cat vs a working cat (~100 to ~20). What do you think the cat is supposed to be doing? (Other than being a restriction :p)
 
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