Question for all those MAF sensor experts!!

MY 01 Cab has been getting check engine lights for the last couple months. Three total times, each time happened while I was stationary (or close to it) and just idling. Same codes each time... Motronic 7.2 Current Fault Codes -------------------------------------------------------------------------------- P1130 Porsche fault code 361 - Oxygen sensing adaptation idle range bank 2 -------------------------------------------------------------------------------- P1128 Porsche fault code 360 - Oxygen sensing adaptation idle range bank 1 First time I cleaned the MAF sensor with some electronics cleaner and a qtip. Second time I just cleared the codes with the durametric. And then tonite I was in stop and go traffic on the highway and the light came on again. I think this means I need to get a new MAF sensor, but before I do that, wanted to see if anyone else has any other ideas or if it could potentially be O2 sensors??? THanks in advance.....

I had same codes, cleaned the MAF a few times and reset the codes. In stop and go traffic, the codes would pop back on every few days. Once it started to cool down, with a cold engine, it started to hesitate and backfire. I quickly changed out MAF and everything has been fine for 9 months now. Rick 99 996C4 87 944S

P1128 Oxygen Sensing Adaptation, Idle Range, Bank 1 – Above Limit P1130 Oxygen Sensing Adaptation, Idle Range, Bank 2 – Above Limit Potential causes: – Incorrect signal from MAF sensor – Intake air system leaking – Fuel pressure too low – Volume supply of fuel pump too low – Fuel injectors fouled – Exhaust system leaking It is not your O2 sensors. You need to measure the air flow over the MAF at idle and at idle and no load (AC off) 3000 RPM. The MAF should read: idle - 12 - 24 ML in kg/h 3000 RPM - 50 - 80 ML in kg/h If it is not within these limits then the MAF is likely bad. If it is within those limits then you likely have an air leak in the intake, or a broken bellow on the AOS.

I had the same codes, cleaned the MAF with MAF cleaner (I doubt there is any difference from what you used, but there might be) and have not had a CEL since.

Loren - Is the airflow measurement something that I can do from the Durametric software? I seem to remember something that you can measure for the MAF but not sure if its the same thing that you mentioned in your post. Would be cool if I could easily measure it to know if the MAF is bad! Thanks

First,I don't think you should have used a q-tip. those wires are very delicate I had to clean my MAF several times before I got it to stop sending codes. The last time I cleaned it I drowned every orifice that piece of plastic had. That did it no more codes since then. I used electronic cleaner.

Loren - I did the measurements tonite with the Durametric. I was within the limits at idle and at 3000RPM. At idle I was ~23.4 kg/h and at 3000K was ~64.2 kg/h. Let the car run for about 15 minutes and the check engine light didn't go back on. I'm at the high range of the limits you had documented...could it still be the MAF??? I have an EVO intake and checked the connection for air leaks and there was none that I could feel/see. What is the AOS?? (you mentioned broken bellows?) Thanks in advance Will

AOS is the Air Oil Separator. Located at the left front of the engine, on the top. A major pain to get at when the engine is in the car. I think the shop time is 10-12 hours as you have to remove most of the intake/manifolds, etc. It is almsot easier and quicker to drop the engine to replace the AOS. I just did mine, and dropped the engine and replaced lifters at the same time.

Recently had codes P1126, P1128 & P1130. Dealer replaced MAF under CPO warranty and everthing is fine.

Dharn55, OT, did lifter replacement fix your strange noise? Rick 99 996C4 87 944S

Most forums you go to you have a thousand amateurs diagnosing your car issues. This forum we have a thousand amateurs and Loren, who knows everything ever. I feel like Rennlist owes Loren a gift. What a guy to have around.

Thanks to the discussion thread about P1128 and P1130. After sifting through the possibilities, I decided to swap to a new MAF sensor. Glad I bought it from Pelican instead of Porsche. Saved about $400. Thanks again for the forum input.

I've got a neat article on the confusing Mass Air Flow sensor problems and what replacement you need right here: http://www.pelicanparts.com/techarti...low_Sensor.htm Hope this helps someone... -Wayne

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Way to go, Wayne! Another great resource. btw, how's your 959 doing?

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Funny you should ask. I have it torn apart in my garage, and then I had the termite guys come today to work in the garage. So, I had to drop it down, pull out the lift, and then tow it out of the garage using the tow hook. It was pretty difficult to do that. Here's the progress on the suspension: http://forums.pelicanparts.com/porsc...-part-2-a.html -Wayne

Real nice car there Wayne. I'm sure there is going to be a lot of enjoyment out of it on the road. C4CRNA mentioned "I don't think you should have used a q-tip" I'll just say never do it. The surface reads parts per million and even cotton can foul the metal coating up. It's a super thin coating of metal. Be it a rebreather or MAF O2 sensor its a very sensitive part. Only flood and flush. Good thing you picked up another because if you scrubbed on the plate with a q-tip I'd concider its reading for use always questionable.