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P0101 & P1811, 20% Possitive Short term fuel Trims Need Help..


carbon02
04-10-2010, 12:12 PM
The 2000 Intrigue has cases where the fault history shows P0101 and P1811 together. It appears that P0101 is the calculated airflow of the car is greater than the MAF sensor. (Unmetered air into the engine? Maybe? )

I've cleaned the MAF sensor with MAF cleaner and it's happened again. Short term and Long term fuel trims are fairly possitive 14-20% I believe indicating a lean condition? But MAF readings to fluctuate on the scan tool. I'd think failure would mean nothing at all on a MAF sensor.

Car idles fine, and fuel trim isn't always that high, but it seems like the PCM is controlling a lean condition.

O2 sensor switches on the scan tool seem to be very good on the tests, so I'm thinking no issues with the O2 sensor feedback.

No noticible vacuum leaks that I can hear or see, so am I looking at unmetered air into the engine.. PCV valve cleaned.

I don't know if P0101 could be causing a P1811 transmission shift issue.
Any thoughts here would be appreciated. I know I might have a transmission issue, but before deciding to dig into that I'd like to get the engine running a little better and address this lean condition.

Thanks-

maxwedge
04-10-2010, 01:38 PM
How do you know the maf is just not bad? Make sure no air is getting in behind maf as you said, first.

carbon02
04-10-2010, 03:07 PM
I 've checked the hoses from the airbox, through the MAF Sensor, and to the throttle body.. Everything is tight.

I'm still getting readings and response frequency from the MAF Sensor. It's possible that these could get lazy, but at Idle of 650-700 RPM I've got MAF of 0.4 lbs/hr. I'd think there would be more irregularity if the sensor was bad, or it would be tripping the codes for Low frequency MAF, and high MAF frequency, but maybe not.

I don't have the other Intrigue today to swap MAF sensors and snorkels, but that's a plan.

After researching alldata it seems like the MAP sensor is part of the calculations for P0101. Alldata mentions this could be an issue, but engine off, key on, MAP sensor readings are about 28-29 inches of Murcury. 14.6 psi, which is standard absolute pressure of the earths atmosphere so that makes sense.

Maybe it is the transmission code that's causing it to run lean.. Any method to get the transmission to relearn the shift delay history without a TECH 2? I'm going to try pulling the battery cables, maybe it takes a lot of driving cycles after clearing a delay code like P1811 to get everything to relearn?

panzer dragoon
04-10-2010, 11:48 PM
MAF
-good time to clean the air filter also.

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