P1124 P1126

[roger_mck]

I have been getting codes 1124 and 1126 recently in my 99 Boxster. I replaced the fuel filter which did seem to help the engines performance, but the codes came back. I took it to a local mechanic who couldn't find any vacuum leaks, he suggested replacing the MAF.

Well, the MAF was already replaced about 10 months ago and I presume it's working OK. To help diagnose what is going on I purchased the ISO version of Car-Code an OBD-II scanner.

The MAF readings with a hot engine at idle are around 3.5g/s which I understand to be low. But the readings do remain pretty steady and increase w/throttle position. The short term fuel trim values on both banks jump around from around -9 to +9 per cent, usually on the plus side.

I have become suspicious of the ICV and ran the engine at idle with it disconnected. The MAF readings jumped up to 5.5 with the engine idle around 1000 rpm. The short term fuel trim values seemed to vary a bit less, between -7 and +7 per cent.

Does anyone else here have experience w/Car-Code? I want to get the O2 sensor readings but it claims that the 'non continuously monitored systems' check for O2 are not complete and it can't provide accurate data. There are probably things I could do with this software - but haven't discovered yet.

Thanks everyone for your help!

[mgoddard1]

I have a 99 boxster and had those codes as well. Removing the MAF sensor and cleaning it with a solvent that doesn't leave a residue fixed it and that was over a year ago. I blasted it with gumout brake cleaner but I'm sure there are probably better cleaners to use that other forum members will suggest.

Edited May 12, 2006 by mgoddard1

[roger_mck]

I have a 99 boxster and had those codes as well. Removing the MAF sensor and cleaning it with a solvent that doesn't leave a residue fixed it and that was over a year ago. I blasted it with gumout brake cleaner but I'm sure there are probably better cleaners to use that other forum members will suggest.

I did try cleaning the MAF, but to no avail. I wish I knew what the proper air flow reading should be for my car at idle speed. I saw somewhere that it should be around 4.8g/s, my MAF is reading about 3.8 or less. But the readings could be accurate if there is an air leak somewhere downstream of the MAF.

For now I'm assuming the MAF is OK, it's less than one year old. I don't really know how to test either it or the idle control valve. I'm wondering if the ICV might be failing to hold a steady position.

[cbracer]

I had those same codes for a long time. replacing the MAF is the only thing that did it. Then 10 months later I took it back to the dealer and they put a new one in again... only this time under warranty because there's a 2 year warranty on parts. whew!