Newbie with some MAF questions

[opinwyd]

I am having a few issues with my 2001 turbo. The problem is undoubtedly the previous owner, but besides that, I have some other issues. The car is throwing a PSM/ABS light after driving for anywhere over like 15 minutes or so. When I got the car it had a BMC filter, so I suspected the MAF may be the issue from the oil on the filter or just dirt. So I pulled the BMC and replaced it with porsche paper ( the car now consistently pulls 1.0+ bar ) and then pulled the MAF and cleaned it thoroughly. After cleaning the MAF, I drove it and the difference was unreal, perfectly smooth shifting, no more strange increased RPM's at idle, no more surging under load, random smoke puffs at startup, or rougher shifting. It felt like a different vehicle all together, but after driving for about 15 minutes, the feeling started to go away back to the earlier symptoms and then the PSM/ABS lights came on again. I tried to run the lights but they dont register as CEL's so I get no code from just a normal OBDII reader. I pulled the bosche MAF again and the part number is the newest 125 one. From what I know the 2001 turbos started with the 123 part number, had problems and switched to the 124 part# mid year, and ultimately to the 125 because the 124's were still succeptible to dirt sensitivity and malfunctions like the 123's were. I also know that the 125 requires some $1500 upgrades to the ECU to work properly with the car. My question is how I can determine if the ugrade has been done? also if the veterans here agree with my assumption that the MAF is in fact the correct diagnosis, or just help in general. Thanks a lot guys!

Edited February 3, 2012 by opinwyd

[Loren]

I think you are confusing the 996TT with Carrera and Boxster series.

The part number for the 996TT has always been 996-606-124-00 as far as I know.

If you are using a different part number then your DME can not adjust for that different part. Start with the right MAF.

The 996-606-125-00 is used with the 997TT but it is a very different air flow system (one per side).

[opinwyd]

I have ordered the 996-606-124-00 Bosche replacement MAF. In case anyone is interested, Porsche was charging $685, I ordered mine from autohausaz and it was $207. I will keep you updated if this fixes the problem. I would definitely recommend no one gets a kn or bmc filter for their 996tt though.

[turbo4 me]

Disconnect the MAF and drive the car- if that fixes your problem, then you know it's the MAF.

[opinwyd]

I did actually replaced the MAF with the 124 oem one, and it does drive much better; however I have not cured the other problems of the cruise control not working at all, no lights no engagement nothing, and also the PSM/ABS Light that comes on after driving for awhile. Not sure what to do for either of these, any suggestions would be helpful thanks!

[Sunnyside]

I did actually replaced the MAF with the 124 oem one, and it does drive much better; however I have not cured the other problems of the cruise control not working at all, no lights no engagement nothing, and also the PSM/ABS Light that comes on after driving for awhile. Not sure what to do for either of these, any suggestions would be helpful thanks!

First of all get your self a Durametric . the hand held OBD2 readers are very very limited. With a Durametric you can just about do everything the OPC can do except code new modules and Keys.

Disconnecting the Maf and driving is an excellent way of checking your MAF. There will be a code associated with the PSM/ABS light.One of the overlooked and common faults is Steering alignment sensor re-calibration. you must do this after any suspension work or geo work. you will get the ABS/PSM light on and the relevant fault code. It is a pain in the *** , but when you get that light up its the only way the DME has of telling you there is a problem with some aspect of the cars well being and can have nothing to do with the MAF its self.

Remember, cruise control, speed conversions. ABS, PSM, traction control, Tiptronic functions all use multiple sensors such as Steering angle, wheel speed, rotational direction and velocity etc. so an ABS/PSM light can indicated you have an associated fault in any one of those areas that is not significant enough to put the DME into limp home mode.

[PhillTrandafilov]

I think that I have similar problem.Had ABS/PSM lights sometimes but after cleaning the MAF they disappear for one or two months.In the last few weeks the lights start to come on every day when engine is hot or after hard ride .I bought brand new MAF from BOSCH,with correct part number ,etc. but light appear even faster-right after start up.Idle is rough when they appear.Durametric says -hot film MAF problem.Air filter is brand new OEM paper,plugs are 25 000 km old.

Any suggestions pls what to do next.In Bulgaria is just one Porsche dealer and 2 services,but with my kind of job is bit hard to visit them.

Should I try to clean the throttle and if so how hard is it?

Any suggestions are welcome.

Regards

Phill.