MAF Replacement Before and After Results

[tXster]

Loren / Toolpants,

I replaced my MAF in my '01 986 S which has 67K on the clock. I have cleared codes 1128, 1130, and P0507 Battery was disconnected when I replaced MAF 986 606 125 01 which was the exact part as the bad MAF. Replaced MAF due to erractic and chasing idle. Car holds steady at/near 1200 RPMs at idle. I ran the car up to operating temp over a distance of 6 miles. I recorded activity before replacing MAF, right after replacing MAF, and after driving with the new MAF 6 miles and up to operating temp. My question is should the idle settle down to normal (650 RPMs) after driving for awhile? Thanks for taking a look.

PORSCHE_BADMAF.txt

PORSCHE_NEWMAF.txt

PORSCHE_NEWMAF_OPTEMP.txt

[tXster]

Attachments are hard to read, here are some direct links to them:

BAD MAF

NEW MAF

NEW MAF OP TEMP

[Loren]

After reseting the DME it will take some driving to get the idle and power curve adopted.

I am surprised that you changed the MAF for an idle problem. The MAF does nothing at idle - you can even disconnect it and it won't make any difference until the higher RPMs.

If you had/have an erratic idle it is more likely a dirty throttle body and/or an air leak in the intake somewhere (loose hose, loose clamp, AOS failure, or oil filler tube failure, etc., etc.).

[tXster]

After reseting the DME it will take some driving to get the idle and power curve adopted.

I am surprised that you changed the MAF for an idle problem. The MAF does nothing at idle - you can even disconnect it and it won't make any difference until the higher RPMs.

If you had/have an erratic idle it is more likely a dirty throttle body and/or an air leak in the intake somewhere (loose hose, loose clamp, AOS failure, or oil filler tube failure, etc., etc.).

Found a slit in one of the rubber sleeves (996.110.686.01), guess the clamp tore into it while I cleaned the throttle body. Was able to cut off the bad area which was right on the edge of the sleeve and reattach. Car seems to run better than it ever has, knock on wood, idle back down with no hesitation or recycling. I'm ordering a new sleeve but will leave the old one on, leaving well enough alone. Anyway, it was a vacuum leak, hopefully my new $250 MAF helps in the higher RPM range. As always thanks for the tips.