so far, even when i baby the car, im getting pretty crappy milage. i have a 1990 iroc-z 5.7L with the g92 option. i took off my cats, and changed my fuel filter. is there anything i can do to improve my gas milage? would a new o2 sensor do anything for me, even though i don't have cats? thanks guys... any help would be greatly appriciated

i think my car MAY be running rich too... im going to pull up some money for a Air/Fuel Guage to see if wuts going on... then if there's something wrong, ill get an AFPR to fix the problem... im still not sure though if i should get a new o2 sensor since i dont have cats... but if it'll help my gas milage, i'll get one

 

Not having cats doesn't have anything to do with the O2 sensor. The computer uses information from the O2 sensor to make mixture decisions. The sensor going bad typically results in an over-rich condition.

Try replacing the O2 sensor and see what happens.

 

i knew what the o2 sensor did, thats why i wanted to replace it cuz i think it's bad... but someone (who i guess doesn't know **** from the answer he gave me) told me that since i don't have cats, to just put a spark plug in the o2 sensor's place because i dont need it anymore... i was pretty sure he was wrong but i wanetd to make sure 100%... thanks lol

 

And I won't try to pass myself off as a TPI whiz, either.

I don't recall off hand if '90 was still MAF or if that was the first year of SD. If SD, then changing exhaust flow characteristics can change fuel mapping response. However, I don't know (no whiz, remember) if that would lead to rich or not. Or even if no cats would change flow enough to affect SD.

A $20 sensor would still be a good place to start.

 

yeah, it's SD, 90 was the first year they took off the MAF