Hey guys, Im not an advance cat in engine work but need some help. I got a 95 z-28, gut cat, freshly built trany and engine(just new bearing seals, nothing expensive.....) but done to the story, I have no problem once the car warms up but when first starting over it seems as if the car is getting to much air. by that i mean its ideling at 400-600 rpms(not stable just going up and down) and if i reverse bring it to say 1000 rpm and let go the gas it kills out b/c rpm drop rappedly down to 300 and will die out. keep it mind its always from a cold start.
from what i have be told.. to believe is the o2 sensor and i need a "dead" sensor? something that says to the computer its working fine b/c the cat is no longer there... but i dono im lost more than ever and tired of reversing and dieing ,starting ,reversing ,dieing.... i need help or im going to shoot my foot soon so i dont have to drive .... alrighty well if you can or have some personal advice or need more info email (lionelb@hawaii.edu) or post please... ight peace

 

its ither the o2 or( run seafoam or replace) or ts ur mass air or throttly postion sensor, some have weird quirks like that when the start to go bad

 

well the idle should be 800 + - 50... so if its between 400-600 the idle is off

 

your O2s arent used until the car actually warms up from a few minutes of idling. a missing CAT will not cause this issue either. i ran without one for over a year on a stock motor and never had issues.

 

opti spark