Fouling o2s
 

Ok, this is the second drivers side O2 that has fouled. I still have the stock o2 on the pass side. Any one have ideas on why it might be fouling? I got a GM o2 before, should I try an auto zone version?

Sucks when your driving and your o2 dies on you. At first i was like wtf then after some trouble shooting driving it was doing exactly what it did last time the o2 died. Very bad stumble till like 1800~+ rpms then it smoothed back out. Had to keep it in third to keep it from shaking its self apart the stumble was so bad. :Dumb:

Are they just going junk(no reading) or are you throwing a code for them? Most the time when people have a o2 code, its NOT the sensor, its something else causing the sensor to act funny.

Throwing a code, scanned it with w/e tunercats recommends as a scan software. First time it was a dead o2(I think they were the ones that came with the car lol.) Wanna say drivers side was reading 42(mv?) and the pass was reading like 850, id have to go look at the logs again to double check exact #s. That was the only code it was showing. Think it might be a bad connection at one of the connectors and or a burnt wire somehow?

Also when I scanned it, I just wanted to start the car and see what the pcm was reading for a code/ #s. Not sure if I shoulda let it go into closed loop or not.

When was the last time u did plugs and wires? Raw fuel can make them read totally lean and throw a code. Could be alot of things really.

Last year when I first got the car, car runs fine when it throws the code and goes into open loop. And its only the drivers side o2 that's throwing a code, the pass side is working correctly it would seem. Should I try pulling plugs and see how they look? Any thing else I could check?

Definaly worth looking at plugs they tell a tale so to speak but good ?

Alright, I might try pulling them tomorrow, ill post pics of them and see what you all think. What should I be looking for on the plugs? The drivers bank should look much different from the passenger side correct?

If i do try and replace should I just get an auto zone one and see if thats the issue? I've herd a bunch of bad about bosch o2s But its like half the price of the dealer part. Would data logs be helpful to anyone?

Didnt end up pulling plugs, after looking at the o2 its some how getting oil on it. The wires were damp with oil. So I think the oil was shorting something out...? Cleaned the connectors and routed the wires differently. The oil has me stumped tho, I already fixed the intake leak a while ago and still dry back there. I think its my low oil sensor(one in the side of the oil pan and its def leaking) but what I don't get is how would the oil be traveling UP the wires cause both the loom and wires up by the oil pressure sending unit are dry. I'm gonna datalog it again in a bit and see if the o2s still reading WAY low.

Oil could ve valves seals but more then likely rings are having blow by check your tb see if oil is coming up through it also

Im saying the outside of the wires on the o2 were oil covered, same with the low oil sensor. Im saying there is a leak external to the engine and leaking onto the o2 wires and running down them to the connector its self.

I might not understand fully what your aiming at but is sounds like your saying there is so much oil in my exhaust gas that its getting pushed out through the o2 in the header and making the oil climb like 2 feet up the o2 wire?

I didn't know u meant external since it's external it should have no affect on your o2 unless you have a bad connector

The o2 should have a weather connector and the end where the wires go into the sensor itself should be sealed.

swap your front o2s and see if the problem follows the o2 sensor

Yes i was saying external sorry for the confusion, I'm not always the best at getting across what I mean. I haven't done a compression test yet but I've never had any smoke a wot or decel so I think my rings are still ok.

I data logged it again and watched it this time, drivers o2(bad one) never got above 120mv and bascially never moved from 100~ where as the passenger side would go from 1 to 950mv. I'm going switch them shortly and then datalog it again. If it follows it, should be a easy fix cause the o2s bad. If it doesn't follow it that means I have a lose or broken wire somewhere?

The car runs fine in open loop, runs like shit in closed loop for like 10 seconds and then goes back into open loop.

Again, thanks for all your help guys, means a lot to a newbie!

Shouldnt you be around .450mV?

Being high like 950mV indicates really rich, while the other ~120mV indicates really lean.

I agree with Joe, swap the sensors and see if the problems stay in those banks. Would indicate other problems.

The passenger side o2 was sweeping faster then you know lol thats why I said it went that high and that low, cause those were min/max #s I saw. So it would seem the passenger side o2 is "working" but the drivers side HARDLY moved from the 100ish range which made me think its dead, so, Ill try switching the o2s and see what happens and go from there.

Stuffing my face atm, after I'm gonna go switch them around, so Ill have an update in like a hour or so.

Ok, switched sides and it followed it. So I'm gonna try replacing the bad o2 with a new one. I noticed something on the gm one, it has 5 wires going into the 02 but only 4 into the connector, the old one and replacement only have 4 on each end. Did the dealership give me the wrong part hence it failing? Ill take pics and post them up if it makes it easier.

Ok, replaced it with a new one, and its fine it seems. Now the o2s shouldn't stay still correct? they should jump around a lot? If they are meant be pretty stable readings something is up with my car cause they jump all over the place. Let me know what you guys think.