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I have a 2012 Chevy Sonic (1.8L auto) with about 35K on the clock. About two months ago I got an oil change; on the first cold (below freezing) day after that, I got a CEL with code P0171, which is:
Quote:
Type: Powertrain - Fuel and Air Metering - ISO/SAE Controlled Location: Bank 1 Description: Fuel Trim System Lean Conditions Causes: No PCM codes set, ECT input from 176-230°F, engine speed 1000-4000 rpm (0-4000 rpm on VIN 1), throttle angle steady below 91%, VSS under 70 mph, purge duty cycle below 80%, then the PCM detected that the LONGFT was over 100, or that the SHRTFT was below 94, either condition met for over 25 seconds
This seems to only happen on very cold days and goes away on its own when the ambient temperature rises and/or the engine has been warm for a while.
Any ideas what could be causing this? I checked the obvious first, and the dipstick and oil cap are seated properly. Would using a different oil weight cause this error? I'm wondering if the tech decided to put in a different weight for the winter and the car isn't liking it...
I have a 2012 Chevy Sonic (1.8L auto) with about 35K on the clock. About two months ago I got an oil change; on the first cold (below freezing) day after that, I got a CEL with code P0171, which is:
This seems to only happen on very cold days and goes away on its own when the ambient temperature rises and/or the engine has been warm for a while.
Any ideas what could be causing this? I checked the obvious first, and the dipstick and oil cap are seated properly. Would using a different oil weight cause this error? I'm wondering if the tech decided to put in a different weight for the winter and the car isn't liking it...
System Too Lean/ Fuel Air Metering is normally a MAF issue. Basically, system too lean is saying that the Fuel/Air ratio contains too much air.
When you say it's cold out, how cold is it exactly? This shouldn't really be happening at 35K miles...
System Too Lean/ Fuel Air Metering is normally a MAF issue. Basically, system too lean is saying that the Fuel/Air ratio contains too much air.
When you say it's cold out, how cold is it exactly? This shouldn't really be happening at 35K miles...
It seems to only happen at ~32F or below. The first time it happened it was about 28F, the second time (this morning) it was around 24F.
I have a 2012 Chevy Sonic (1.8L auto) with about 35K on the clock. About two months ago I got an oil change; on the first cold (below freezing) day after that, I got a CEL with code P0171, which is:
This seems to only happen on very cold days and goes away on its own when the ambient temperature rises and/or the engine has been warm for a while.
Any ideas what could be causing this? I checked the obvious first, and the dipstick and oil cap are seated properly. Would using a different oil weight cause this error? I'm wondering if the tech decided to put in a different weight for the winter and the car isn't liking it...
I have a 2012 Chevy Sonic (1.8L auto) with about 35K on the clock. About two months ago I got an oil change; on the first cold (below freezing) day after that, I got a CEL with code P0171, which is:
This seems to only happen on very cold days and goes away on its own when the ambient temperature rises and/or the engine has been warm for a while.
Any ideas what could be causing this? I checked the obvious first, and the dipstick and oil cap are seated properly. Would using a different oil weight cause this error? I'm wondering if the tech decided to put in a different weight for the winter and the car isn't liking it...
If they opened the air filter box or anything like that, there is also the possibility that a vacuum hose got disconnected.
Indeed.. This is a code that is not one that you can look at from the code alone.. This is where a scanner that can read the freeze frame data of what statuses were when the condition was logged will help diagnose.
The important part of the error is this.
PCM detected that the LONGFT was over 100, or that the SHRTFT was below 94
What we don't know, is which was the case.
The main things that get focus on something like this are, as others have mentioned.. MAF sensor problems, a vacuum leak, fuel system issues (Weakening fuel pump, fuel filter problem) or an exhaust system leak.
None of which you really want to deal with when your car is under warranty. Other than maybe looking under the hood to see if there's a hose disconnected, or as you mentioned, the dipstick or oil cap being loose.
My guess is that perhaps you have a leak in a gasket (Intake would be my guess) that is sealing itself when the engine comes up to operating temperature. so, the engine is getting more air than the MAF is indicating, until you come up to temp and it basically seals itself up.
If your bumper to bumper warranty expires at 36k you better not drive it anywhere except to the dealer.
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