Would running too lean throw codes?
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Would running too lean throw codes?
I had a "too lean" code some time ago, but don't know if it's serious or not. Would something like that cause damage to my car before CEL comes on?
And would clearing codes affect the readiness status on my car? If it wasn't a coincidence... last time I did that all my readiness codes got cleared too...
And would clearing codes affect the readiness status on my car? If it wasn't a coincidence... last time I did that all my readiness codes got cleared too...
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The CEL comes on when the ECU can no longer compensate for a lean condition
The trim has a range of +-25%, if you get ouside +-10% you'll get an error code but no CEL, if you get outside the +-20% range you'll get a CEL. It's not until you go over the maximum trim +-25% that damage to the engine can occour because the ECU can no longer compensate.
Resetting the codes resets your trim, readniess, everything.
Resetting the codes resets your trim, readniess, everything.
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Unless you're sure it's due to a bad sensor, I wouldn't reset it
If it's actually runing lean for some reason and not just responding to a bad O2 sensor or bad IAT sensor, reseting it will force it to run lean again until the trim levels re-learn. It takes some time for the trim levels to adjust, during which you could be running dangerously lean. Another words, I leave it alone until you can figure out what's wrong.
If you have access to a VAG, do some logs. Check you MAF and IAT readings for one. You can also check the O2 sensor readings, but those can be somewhat confusing if you don't know what you're looking for.
If you have access to a VAG, do some logs. Check you MAF and IAT readings for one. You can also check the O2 sensor readings, but those can be somewhat confusing if you don't know what you're looking for.
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Re: Unless you're sure it's due to a bad sensor, I wouldn't reset it
It should not be a vac line problem. I had that before and had the vac line replaced by the dealer. I suspect it could be from a bad sensor or a code that might be thrown when I spwapped ECU's. Stock to APR. (stage 1)
And yes you're right I don't know what I am looking for. However if I don't do it myself the dealer probably will replace the hoses, all the sensor and as soon as I put the APR chipped ECU back in, I'll be exacly where I have started.
Can anyone point me to any resources as to how to look for sensor, etc. problems.
And yes you're right I don't know what I am looking for. However if I don't do it myself the dealer probably will replace the hoses, all the sensor and as soon as I put the APR chipped ECU back in, I'll be exacly where I have started.
Can anyone point me to any resources as to how to look for sensor, etc. problems.
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From: NC
There's more than one vac line to worry about. Check the one at the rear of the intake manifold
that leads to the FPR. I'm pretty sure you can have a leak on that hose without throwing a CEL since it runs right to the FPR. I had this problem last week.