dadenkern
11-06-09, 03:42 PM
2001 non-sport, 166,000 miles
Symptoms
- P0411 code several times a week
- Rough idle when started cold
- No issues once the engine was warm
Solution
- Replaced MAF sensor
One trigger for the P0411 code is failure to detect a lean condition during a cold start as it should with the extra air introduced by the secondary air injection system. During a cold start the MAF sensor must have been mis-guiding the computer causing an unexpected fuel-air ratio as measured by the O2 sensors. Once the car warmed up and closed-loop control was established the car ran fine.
Symptoms
- P0411 code several times a week
- Rough idle when started cold
- No issues once the engine was warm
Solution
- Replaced MAF sensor
One trigger for the P0411 code is failure to detect a lean condition during a cold start as it should with the extra air introduced by the secondary air injection system. During a cold start the MAF sensor must have been mis-guiding the computer causing an unexpected fuel-air ratio as measured by the O2 sensors. Once the car warmed up and closed-loop control was established the car ran fine.