Volvo S60 2006, P0101 and P2188; MAF Flow Circus

[JohnDAntonio]

hi everyone,

Interesting issue to resolve - I have a rough idle that smooths out as I pick up speed. I only have issues starting up but none on the highway, and I am occasionally stalling at startup. I've been getting the P0101 popping up, confirmed by the OBD tool, along with the rich idle at bank 1. I played parts dart and replaced the MAF Flow sensor with an OEM part and reset the CEL. Everything runs smoothly right after the reset but within a day or two the CEL will come back on with those two codes.

To check for the issue, I've sprayed soapy water to check for vacuum leaks but this does not seem to be the issue, and I would expect a lean code with this anyway. I've also attempted an ECU reset by unplugging the battery and letting it drain before reconnecting. In addition, I've been able to have some luck with fuel injector cleaners to smooth out the rough idle but the code always returns. I've also changed the air filter and cleaned the new MAF, and the root cause doesn't seem to be either. I know my spark plugs are old and need to be changed, but I cannot see why that would cause the aforementioned codes. I was also thinking a leaky fuel injector, but I'm perplexed by the pairing of these two codes and what it could mean. I'm very close to sending this off to the mechanic but my gut tells me this is a simple fix that could be sorted out with the right guidance.

Please let me know if you have any suggestions!

Thanks!

[mando]

I'm in almost the identical boat with my son's 2007 S60. We had the MAF replaced with a Bosch unit my a certified tech and the issues cleared up....for that day. Next day after sitting at College, the car stalled when started, he had to keep revving it. Ran fine on the highway home. P2188 when he got home. He cleared the codes accidentally and we took it out for a ride when I got home, no issues. Checked vacuum lines with brake cleaner, no apparent leaks. I'm sure it will come back tomorrow.

[jimmy57]

Look for cracked intercooler or any of the plumber from turbo to throttle. Turbo will pump air at idle through any possible leak point on the parts of intake path listed. When the air leaks the signal for MAF will be outside (high) of mapped signal range and the fuel will be metered for that air but that amount of air (oxygen specifically) will not be in cylinder so it is rich.