QuestionQUESTION: I've got a 2004 S60R with about 69,000 miles on it. I've upgraded the ECU software with an after market upgrade and have experienced about 2 1/2 years of fantastic performance. Yesterday, while driving on my normal freeway commute, I felt what seemed like a brief ignition miss and then everything seemed fine. However, when I got off the freeway, I noticed that the car didn't have any pickup what so ever. It almost seemed as though there was no timing advance taking place. The car idles just fine and doesn't seem to be running rough at all. I checked the engine for anything obvious like a leak in the intake plumbing, but didn't notice anything or hear anything that sounds like a leak. I'm also pulling a P2188 code. Any ideas?
ANSWER: David, your code is indicating a MAF (Mass air flow sensor) reading out of range. Did you by chance install a K&N filter kit when you did the upgrade?
Mark
---------- FOLLOW-UP ----------
QUESTION: I did. However, since yesterday, I was able to pull another error code. Its indicating a P0235, engine turbocharger overboost. I was able to reset the error code with my scan software and the problem goes away until I push the car under load to about 4000 RPM. Then it reverts again to the same condition. I'm thinking it could be the TCV (turbo control valve). From what I understand, that's a common problem with the Volvo turbo engines. I'm going to try to replace that and see what happens. Any thoughts?
ANSWER: David, I'm concerned the K&N oil may have contaminated the MAF and it's not reading correctly.
I doubt the the charge pressure regulator is the problem. Always possible though if stuck wide open. I would look hard at the MAF readings first.
Mark
---------- FOLLOW-UP ----------
QUESTION: So I replaced the turbo control solenoid and as you thought, no difference. I've looked at the readings of the MAF while driving and it seems to have a steady increase in air flow. How can I be relatively sure it is the MAF? Is there another test I can do? I've already tried cleaning it with MAF cleaner but it hasn't resulted in any benefit. If anything, the idle seems a bit rougher.
Answer David, MAF cleaner??? What the he... is that? You should never spray anything on that platinum wire.VBG
In all my years of working with MAF's including looking at the waveforms and voltages, I've never found a conclusive test for marginal ones other than this: "replace with known good part and retest." Sorry........
Mark
