eli_youssef

This issue is starting to drive me crazy, hopefully you guys can help. I have a '03 e500.

I got a check engine light, scanned it, came up with bad MAF sensor, the car was running rough. So I bought an aftermarket MAF off ebay, installed it and then started the car and all was fine for the first 5 or 10 minutes then the engine was very rough, started jerking and eventually shut off. I figured it was a faulty maf, returned it and bought an oem bosch unit online. Meanwhile I reinstalled the old maf until the new one came in and it was fine. I finally got the new bosch unit today, I installed that and right off the start it was rough, drove smooth for 5 minutes but the moment I stopped, the car shut off. Everytime I started the car it would rev itself and then shut off, I scanned the car and got P0101 which is the maf again. Are all these MAF sensors that i'm getting faulty or is there another issue? 2 units and the same problem, either I have really bad luck or there's something else. Could it be the crank position sensor?

Sorry for the winded post, I don't know what to do, please help.

eli_youssef

Anyone?

radaddict

The CPS would throw a different code. Check the wiring to the MAF - make sure the connectors are clean and the wires are not damaged in any way. If the engine runs better with the original MAF, you could try just cleaning the MAF with MAF cleaner (don't try cleaning it with anything else). Also, check your air filters as well.

eli_youssef

I'll check the connector but if it was the connector or air filter, wouldn't the problems occur with the old maf too? I knew I was taking a chance with the cheap ebay part but with a bosch unit too? I cleaned the old maf with maf cleaner and reinstalled it again.

radaddict

I'm not sure I'm understanding... You replaced the MAF becuase the engine was running rough and you had the P0101 code, correct (are you getting any codes in addition to P0101)? P0101 indicates a problem with the MAF or MAF circuit. If the problem is not corrected with a new MAF, then the problem is elsewhere, but MAF related - hence the suggestion to check your wiring and air filters.

Of course, it is possible you mananged to be unlucky enough to get 2 bad MAFs.

That's about the extent of what I know regarding the MAF. Hopefully someone else with more knowledge/experience will chime it.

eli_youssef

Yes, when I first got the code, it was running rough intermittently, both times when I changed to the new maf it ran very rough, constantly, even stalled a few times. I'm back on the old maf, I started it and it was fine.

Hope that makes more sense.

radaddict

Okay. So, back to the old MAF (that you cleaned) and it's running fine. Have you cleared the code and has it come back? If it's running fine now, then I'd call the problem fixed and it was just a dirty MAF.

Since both new MAFs made the problem worse, are you certain you ordered the correct part?

eli_youssef

I started the car after cleaning and reinstalling the old maf, no code appeared and it idled smooth for a few minutes. I haven't driven the car since last night.

I am positive I ordered the right part, part numbers match, I triple checked everything was right when ordering the bosch unit.

radaddict

Hopefully, cleaning the MAF fixed the problem.

john0183

Is there a diy on cleaning the maf I would like clean my maf .