steve40th

I went cruising last night and received a code 13 , indicating left O2 sensor, on dual censored cars running lean. Previously I had a code 64 a couple months back. So I swapped the sensors and the problem went away, till last night. Granted the codes are different, but its saying the same thing, O2 sensor lean or open. So, what would cause an O2 sensor (DENSO 3 wire) to go lean? I think it is the O2 sensor as the problem moved from the right ( 64 code) to the left ( code 13).

tomtom72

Seems to be your line of reasoning is correct. The code seems to be following the sensor. Just for the heck of it did you have a look at the plugs? Do they agree with the sensor? Does the car smell okay at the tail pipe, no lean smell? Those would be the other things that I would have looked at to give me a little more info...ya know just to be sure I didn't overlook something. The only other thing I can think of is checking the wiring to the sensors....oh joy!...as an outside shot.


Tom

Lichen

I have been going through the same problem with the Denso 3 wire. Did you get yours through Caspers Electronics? I ask, because when we went to replace the bad sensor, none would match up. Turns out, some clown at Caspers reversed the plugs on the sensor and harness! Ended up having to cut the wire and plug off of the old sensor and have them soldered to the new sensor. Anyway, seems to have solved the problem.

steve40th

Tom, The plugs are messed up on this side now. The exhaust did put out black smoke again. And you could smell the exhaust too, intermittenlty. I think the sensor may have just a bad wire or is something simple. The only definite symptom is the fact the sensor had a code when it was on the right and now on the left. That cant be wiring from the plug to the ECM , power etc. It IMHO can only be from the sensor itself.

steve40th

Mine is a Delphi sensor, and I personally dont think they came from there as I bought them from a CF member and I dont remember Caspers being a part of the conversations and from the bulder of the harness.
That is odd what the person did. Arent the sensors pre maid? Or did he do the sensor harness for an upgrade to Heated and have the ground and power backwards? It will work, just going positive to negative or the other way?

mseven

I would try a different one, when I had asked the wiring question with TPIS etc. I was informed it should not make a difference. The other thing I would be looking for is if anyhting has changed in the set-up for it to be seeing less fuel.

steve40th

Try a different manufacturer of the O2 sensor? Or just get another O2 sensor and put her in? I cant find Delphi, so AC Delco is supposed to be the same part as they are made in same factory.

mseven

If I had another handy I would try it first. I think the AC would be just fine, I have a bosch 3 wire that seems to be fine (not sure but, aren't the ac 's made by bosch?). However, I would also be looking for changes (ie. fuel press. injec. etc.),. and through some scanning to be sure of the lean condition source.

steve40th

I had problems with the right side. When I moved the sensor all was fine, now its the left side. The weather pack connector was loose when it was on the right side, as the wire came out, so it wasnt getting good voltage readings to the ECM. When I swapped I fixed the connector, and the problem has been gone for a while. Now the problem is on the left side, and the codes say low voltage/lean condition. That is why I think it is the sensor now. Maybe it was dropped originally? I dont know.
But I want to stay the same sensor, but since DEPLHI is not around, apparently the factory that made DELPHI is AC/DELCO parts too.
When the sensor was working both sides looked great on the scanner, almost dead nuts on. Injectors dont leak, fuel pressure is 43psi, plug wires are new and I use A DELTEQ system.
I am hoping the diagnostics is just what its telling me and all I have is a bad O2 sensor.

bobmic93

Steve, just slap in a single wire back in , just to see if it works. I gave up on the heated 02s. a

steve40th

I was thinking of that, but my car will not go into closed loop with single wires. Now if one is heated and puts the Vette into closed loop, that would be interesting. But then you have two different sensors reading differently.

RRT vette

If they have a good many miles on them, I might be inclined to just purchase a new pair of heated ones. This way you will know that the sensors should be good. While there check the wiring and connections.

As mseven suggested, is there a change in the way it runs? Any exhaust work done lately..maybe a leak before the sensors.

steve40th

They have maybe 1500 miles on them.
The tune is fine, and the TTS datamster shows it is running good. I think the sensor went bad during installation. I originally had problems with the connector being loose.
I did have a leak after the sensor, as was posted in a thread a while back. When I put smoke into the exhaust, nothing came out other than in the spot way past the sensors. Right now they are heated sensors.
http://forums.corvetteforum.com/show....php?t=1577509
The exhaust leak is fixed.

RRT vette

I see, I do know that these sensor are very sensitive and one being dropped or hit against something, can ruin it.

mseven

I thought about that myself but I believe if there was an exhaust leak, and the 02 was "seeing" oxygen it would show a rich condition as the ecm would try to compensate with more fuel. As you stated w/f.pressure and inj. being right, I would just try another 02 sensor and definetly get a heated one to work. It also sounds like the weather pack may be suspect.

steve40th

I know if you have an exhaust leak prior to the O2 the engine will assume Lean and dump extra fuel to compensate.
Mine I believe the weather pack connector, or the O2 sensor may have been dropped. Again it doesnt take much to ruin these things.
I found a AC Delco here for 80 dollars. The dealers wanted 172, 174 and 134. Insane out here in Hawaii.
I would have gone through the Kansas guy , but I need it by Friday as we are SCCA racing this weekend.

bobmic93

O.K, I have one heated sensor on driver side and one single wire not heated on other side. Car still goes into closed loop and it makes sense. ECM has to get a reading from one or the other to send the car into closed loop. Obviously the heated one will always trigger the ECM to call for closed loop. Myself, I just got sick of screwing around with it and left well enough alone. I mean once in closed loop the heated action is no longer needed and each bank will be monitored by the ECM.

mseven

I agree with those 02's being a bit delicate and leaks leading to ecm compensations (rich or lean), I had similar experience with leaks myself, mine went to a rich condition. A closer look at the weather pack probably wouldn't hurt ........BUT, 172, 174 even 80 bucks for a new 02 is little steep (ouch) Sorry to hear it can't become more benficial to get a parts place here to ship it 2nd day cheaper. Hope that gets it right for you, and good luck this weekend...

steve40th

The thing with the sensors is that I have a DELPHI, which is a AC/DELCO part. I couldnt find the DELPHIs, so I looked for AC/DELCO.
I could have bought 2 new DENSOs, or Boschs, but people tend to favor the AC/DELCO's and since the engine is a little more than stock, , I wanted to make sure the sensors were the best I could get without going to a wideband stand alone engine management system.

Lichen

I don't think the the brands have to match. I finally solved my problem. I think that my original right O2 sensor never worked. Replaced it with a Dodge sensor and all is fine now. Just have to blow the carbon out from running so rich.