P0102 MAF malfunction, terrible idle, but car pulls like wild animal.
Thread Starter
Member
Joined: Apr 2017
Posts: 86
Likes: 7
From: New Zealand
C55 Wagon Midnight Blue, SL55 Brilliant Silver, E55 Designo Mystic White
P0102 MAF malfunction, terrible idle, but car pulls like wild animal.
Was trying to determine why surging idle so uploaded another tune, and immediately got CEL P0102 (Low Voltage MAF), hot smell like when headers were brand new, still idles very badly, but once catches its breath. pulls like not supposed to, gobs of torque, sometimes cuts out maybe to protect itself.
Installed new MAF, code gone immediately, car runs fine again, but back to very conservative power.
So I took the new MAF out and put the 'bad' one back in, CEL, thrilling torque, but bad idle and sometimes cut out or off again.
Not sure what is wrong with bad MAF, but it is like race tune.
Hot smell suggests running lean... The extra torque obvious on startup, car dips more sharply when lightly blipping throttle at standstill.
Anybody else same experience, and/or am I going to destroy the motor running it like this?
Installed new MAF, code gone immediately, car runs fine again, but back to very conservative power.
So I took the new MAF out and put the 'bad' one back in, CEL, thrilling torque, but bad idle and sometimes cut out or off again.
Not sure what is wrong with bad MAF, but it is like race tune.
Hot smell suggests running lean... The extra torque obvious on startup, car dips more sharply when lightly blipping throttle at standstill.
Anybody else same experience, and/or am I going to destroy the motor running it like this?
Last edited by idlebumski; Sep 12, 2021 at 06:00 PM.
Senior Member
Joined: May 2007
Posts: 457
Likes: 61
asdas
With the bad MAF you're running open loop. With the good MAF you are running closed loop. If your performance drops off that much between going open and closed loop, you likely have a running issue while running closed loop that is not bad enough yet to throw a code, but is affecting your performance. Long term it is not a good idea to run your engine open loop all the time. If you are unfamiliar with what open loop and closed loop mean, there's plenty of info online.
MBWorld Fanatic!
Joined: Jun 2009
Posts: 3,040
Likes: 125
From: Atlanta Metro
Current: C217 V12TT AMG Previously: C55 AMG, SL65 AMG
Is the MAF an MB/OEM branded one? I remember hearing that aftermarket MAFs (even if almost-the-same) could cause issues on these engines. I replaced the MAF once or twice when I had my C55.
Thread Starter
Member
Joined: Apr 2017
Posts: 86
Likes: 7
From: New Zealand
C55 Wagon Midnight Blue, SL55 Brilliant Silver, E55 Designo Mystic White
yea, the bad maf was a bosch unit. the car would be perfect like this, except that it does cut off completely very occasionally, which is dangerous.
