Unique Problem - Bank 1 Overcorrecting (Rich)
I know it might not pertain exactly to you but it's more of a general statement for others in the same boat. Basically pointing out that the lower o2 sensors _are_ used for corrections.... When I had non foulers installed my ECU was adding fuel even though the upper widebands were showing rich. I would imagine a clogged cat or any kind of leak after the upper widebands would cause the same problem. Pulled the nonfoulers off and the A/F is now dead on 14.7 and no more overcorrection.
Last edited by djamps; Mar 26, 2011 at 08:27 AM.
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Joined: Sep 2004
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From: Buchanan, MI
A Thought
From someone who has absolutely nothing to do with this issue since I have no mods at all. Just wasting time today reading and thinking about this problem.
At work we just built/shipped a fairly advanced machine that tests these A/F sensors performance to Bosch in SC. Neat stuff. It had a robot that loaded/unloaded the sensors 10 or 12 at a time, LabView running the tests.
Anyway, the thought occurred to me that maybe the ECU is screwing with the A/F correction intentionally as a test. Ramping the A/F up and down and charting the result. Is this plausible?
At work we just built/shipped a fairly advanced machine that tests these A/F sensors performance to Bosch in SC. Neat stuff. It had a robot that loaded/unloaded the sensors 10 or 12 at a time, LabView running the tests.
Anyway, the thought occurred to me that maybe the ECU is screwing with the A/F correction intentionally as a test. Ramping the A/F up and down and charting the result. Is this plausible?
I've just gone ahead and roughly chronicled the entire saga that hunting this gremlin has become - complete with point-by-point details of the problem and every major test that has been conducted with their subsequent results. It's all organized nicely in the attached Word document for anyone that is interested in helping me solve this problem.
I'm serious about this: I am going to give $200 to whoever successfully identifies what is causing all of this and leads me to the solution.
I'm serious about this: I am going to give $200 to whoever successfully identifies what is causing all of this and leads me to the solution.
also, mine would be difference since my haltech widebands are running the corrections and not the oem ecu like in your case so it probably doesn't apply to my situation.
what is the channel name for those? I logged every CAN channel that haltech would allow me to log so i'm sure i have it somewhere.
also, mine would be difference since my haltech widebands are running the corrections and not the oem ecu like in your case so it probably doesn't apply to my situation.
also, mine would be difference since my haltech widebands are running the corrections and not the oem ecu like in your case so it probably doesn't apply to my situation.
Sensor 2 for both banks. The OP was dealing with stock ECU... haltech is a completely different animal, agreed... but one would think it wouldn't completely ignore the downstream o2 sensors. At least in the case of the stock ECU (or osiris flashed) the downstream sensors sometimes take priority for corrections.
ya, on the haltech the rear o2 sensors do nothing (as well as the fronts do nothing) except for keep the ecu happy. Ive had them out of the car with no issues except a CEL code.
^ This seems to be a likely culprit if the latter statement is true. If there is a leak between the upstream and downstream O2 sensor and the stock ECU is correcting for it, then a rich O2 value may still result in overfueling.
How do that bank's plugs look? I've got a similar issue and noticed my plugs say the opposite to what code is being thrown (p1283 for 3 ultra rich plugs). I'm guessing there is something tricking the ECU to feel it can't dump enough fuel in to correct. I too have changed both O2's so I'm searching for a place that does leak testing (smoke machine).
I was going to guess it was tune related before I even looked at this post.
After driving my car for a while, I think the car needs to be driven on the road or something. A steady driver on the dyno and the codes may not come up.
Loads vary, I don't think a dyno can replicate those situations.
After driving my car for a while, I think the car needs to be driven on the road or something. A steady driver on the dyno and the codes may not come up.
Loads vary, I don't think a dyno can replicate those situations.
i had the car tuned and then driven by the tuner for a few miles, then he decided to tune some more. After a few weeks he got the tune to the way he thought was good and after 60 or so miles of spirited driving i managed to pass emissions and now about 200 into it without any check engine lights. I would def say this is tune related.