new member with ?s

[travislee91EB]

i have a 91EB...it has lost a lot of it's power, it has 150,000 on it but it ran great when I got it last year...i ran my code reader on it and it told me the O2 was bad so I replaced it, now it's blowing the black smoke again...what could be causing the O2 to go bad so quickly

 

[brttwttnr]

if you have a blown head gasket,the silicone from the antifreeze exiting the exhaust would tear it up. But if you had a blown head gasket you would have oil & antifreeze mixing and a loss in power. Off hand thats all I can think of welcome to the site and do a search on it you'll turn something up good luck.

 

[Josh]

try cleaning your MAF. If your MAF is dirty it can cause the PCM to use a bad A/F ratio.

 

[travislee91EB]

well thanks for the tips but I checked the oil and water and they aren't mixing...i also tried cleaning the MAF, it was already clean...what about the EGR

 

[Josh]

My truck doesnt have EGR Your MAF may be bad too. I have a Pro-M that was bad out of the box. Got it recalibrated and it worked fine for a while and it seemed to be getting worse again so I went back to stock. I also tried porting a stock MAF and my truck as blowing black smoke to. Go to the junkyard and pick one up. Couldnt hurt to have a spare.

 

[travislee91EB]

that's an idea...they pretty check at the yard?

 

[travislee91EB]

from what i've seen from other users it looks like a fuel pressure regulator

 

[Josh]

mine was 25. FPR might be a good place to check. They are spendy new so pick up one of those as well when your at the junkyard.

 

[410Fortune]

check fuel pressure
clean the MAS even if it looks clean, resett he PCM by disco the battery

An 02 sensor code that keeps coming back even with a new 02 sensor is not the fault of the 02 sensor, it is the sensor doing its job telling you the air/fuel is wrong.

I second the fuel pressure regulator, but instead of throwing $$$ at it you can check the fuel pressure first...

 

[travislee91EB]

well just want to post an update...it was the fuel pressure regulator...funny story though...the wife asked to fix it while i was at work, i said sure...she calls me freaking out because she snapped the "hat" and she had to be at work in 1 hour...she was going crazy...got to credit her though she did take it off and put it back on