I own a 2006 S60 2.5. A year ago my check engine light came on and the code indicated a faulty air mass meter. I replaced it and the code came back right away. The dealer put the old meter back in and did a smoke test. He found a vacuum leak in the air intake hose and replaced the hose. Problem solved.

Two months ago, I had major service work done - new timing belt, water pump, plugs, A/C condensor, electric cooling fan unit, oil, and filter. Car ran great. Two weeks ago, engine began idling rough and the check engine light came on. The code reader indicated air mass meter. Yesterday, I had a new meter installed (Bosch). Today, engine idled rough again and the light came back on. Code reader said air temp sensor malfunctioning (it has a new one). What else should we be looking for? More vacuum leaks? Anything else?

 

I replaced my air flow meter yesterday and today my check engine light is back on same code!!!!!! Anybody got answers?

 

Did you clear the codes after installing the new meter? I'm having a smoke test done on my vacuum and air intake system to look for air leaks. Vacuum/intake leaks can cause an air mass meter trouble code.

 

Yes the codes were cleared, and the same codes have reappeared. Maybe I'll do the smoke test also. Didn't think about that.

 

My smoke test yesterday showed no vacuum/intake leaks. The technician cleaned all the electrical contact points, then did a two day cold start, warm start, test drive, restart, etc. and no codes showed up. I picked the car up this morning and am monitoring my driving habits, outside air temp, etc. So far, so good. I'm not convinced my problem is solved. I will keep you posted. I did have a similar problem a year ago (MAF malfunction, new MAF installed, codes came back). That time, they did do a smoke test and found a leak in the main air intake hose which triggered the MAF fault code. Let me know how you do. God bless . . .

Jim

 

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I think this is now solved and want to post an update. At the beginning of the problem, the ECM codes for my S60 2.5T were 120, 121b, 212c, 216D, 21EO all indicating MAF and fuel trim. A smoke test was done by an authorized Volvo dealer and showed no leakage. A new MAF was installed. The CEL and the same codes came back.

On 1-29-10 I took my car in to my local import repair shop. They removed the intake manifold to clean throttle body and to inspect/replace the oil trap (PCV). They found that the oil trap box was clogged with carbon and full of oil. They also found a cracked breather tube from the trap to the valve cover. They further discovered a cracked tube in the heated breather pipe under the intake manifold. They replaced the oil trap and seal, the breather hose, and installed a new heated breather pipe. The throttle body was cleaned. They were surprised that with so much clogging and leaking there was no oil being forced through any of the engine seals.

I picked up the car on 2-3-10 and have put over 500 miles on it under various road an weather conditions. It runs great!

I hope this experience and the outcome can be a help to others experiencing similar problems. God bless.