Hey folks. I have a 2005 Volvo S60 2.5T, 155k. It's my spare car don't drive much, maybe once every two weeks. Drove it today for a 15 minute drive, ran fine but noticed idle bouncing very slighty at traffic light. I parked the car for about an hour and when I started up to drive home, it sputtered like it was out of gas - would barely move. I shut it down, waited a few minutes, and gave it another try. It started idling ok and I made it home without issues. Checked codes when I got home - P2188 system too rich at idle Bank 1. I'll check for vacuum leaks but am guessing MAF. Any thoughts before I buy expensive swedish parts? Thanks.
vacuum leaks, which cause too much air to get in , would cause a LEAN mixture.
you could have:
- dirty air filter
- restricted exhaust
- stuck injectors.
Why not hook up your scanner again and look at what the MAF g/s readings look like?
Maybe even pull up the MAF, the LTFT, and the STFT. If your scanner has graphing abilities, graph all 3. (if you can't graph it then just look at the data).
Pull up the ECT data too.
Watch the ECT to make sure the car is at operating temp and then look to see what your MAF is reporting at idle.
If the MAF sensor is reporting around 2.5g/s at idle but your fuel trims stay in the high Negatives while idling after several minutes, I can't see how you can blame the MAF sensor.
However, if the MAF sensor is overreporting the intake airflow, and reading above 3g/s at idle, then you can suspect the MAF sensor.
If the replacement MAF sensor is expensive, you can try cleaning it.
People have differing opinions on how a dirty MAF sensor affects the engine.
Some say it causes the engine to run lean.
Some say it causes the engine to run rich.
I'm of the opinion that they're both right. At idle the dirty MAF will overreport the airflow but at higher rpms (higher airflow) the dirty MAF will underreport the airflow.
(that's why I suggested graphing it)
In your case, the P2188 code is saying "system too rich at idle".
So maybe the repair will only cost you as much as a can of MAF Sensor cleaner
Time for a new scanner. Mine is about as basic as they come. Going to get a can of MAF cleaner now and we shall see.
Air filter was clean, there was some trash in the airbox, didn't visually see any bad vacuum hoses but will check further if no joy on the cleaning.
Thanks for all the suggestions - really appreciate the experienced insight.
Well, if you do clean the MAF make sure to use MAF cleaner. The other stuff @MountanManJoe mentioned.
