Dillon93dillon

So today was the day to go get the exhaust done on my 5.3l,

The exhaust shop didn't do the best job.. No check engine lights when he pulled it into his shop, but when he was workig on it and hooked up my o2 sensors it had a check engine light and was running like sh*t! I knew it didn't sound right when he Pulled it off the lift.. But anyways I figured I'll see how it drives, seemed OK but kinda doggy..
As I was close to home it was stalling and inning horrible still check engine light.

I have a question, I believe the o2 sensors I have are for after the cat. Would these not work correctly if I used them for the front ones?

And I disconnected the battery when I got home so I forgot and couldn't Pull any DTC s

Old Geezer

iTrader: (3)

If there are codes stored, hook up the batt and pull them.
Did the exh genius swap the plugs on the sensors???

Dillon93dillon

I should check that but I don't think there long enough. Would runnIng o2 sensors that are made for after the cat work the same? Or are the fronts and rears different

My obd2 port does work, but the scanner says no codes. And my light Is off

rennat_2006

iTrader: (10)

Got over there to do some diagnostics on dillons truck today...
-Found that the FPR was bad, Had fuel coming out of the vacuum line and into the intake manifold. Replaced and runs "ok" with the o2 sensors disconnected.
-Found that the exhaust guy had screwed up the o2 sensor wiring, Had bank 1 and bank 2 flopped. Flopped them to the correct banks and plugged them in.

Like Dillon mentioned he thinks that he has post cat o2 sensors in his precat o2 bungs, He is not running any cats so all he is running is precat o2's and supposely the post o2's have been deleted from the PCM.

Heres the problem, With the o2's disconnected it will run and idle at like 600-700rpms where it should but a little rough. Driving it with the o2's disconnected it seems to be way down on power. With the o2's connected it starts up and idles fine for like 30 seconds or so until the pcm starts reading off of the o2's and then it goes to ****. Wont idle and will barely run, You have to keep the rpms at like 1500 rpms or above and it is puking smoke and loading up really bad.

I had my laptop with autotap on it hooked up and got some screen shots, Hopefully you guys can look at the live data and something will catch your eye. I noticed that both bank 1 and bank 2 fuel trim goes to 54.7% and the MV's for both o2's go to 0mv's. Im really wondering if running the post cat o2's in the precat location will do this?

Heres some screenshots from autotap

Dillon93dillon

I can only think that the wrong o2 sensors are hooked up. Has to be a difference between pre and post voltages or something

Old Geezer

iTrader: (3)

Plugging the post cat wires into the pre cat sensors will cause problems.
Start over on hooking up the sensors..

psiconversion

iTrader: (5)

What O2s are you running (Which connectors are on them, flat black, square black, square white, etc.)?

Jon
PSI

Dillon93dillon

Currently square black need to be white