Error Codes P1128 And P1130

[Dharn55]

On my friends 2000 996 he has been getting CEL's which my Durametric shows error codes P1128 (Oxygen Sensing Adaptation, Idle Range, Bank 1) and P1130 (Oxygen Sensing Adaptation, Idle Range, Bank 2). I have cleared them several times but after a week or two the CEL comes back on. Anyone know what might be causing these codes/errors?

[Loren]

Covered many many times here...

– 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

Likely causes are air leaks - like AOS, AOS bellows, oil filler cap, or disconnected /loose intake hoses.

Could also be a bad MAF but that is easy to check with Durametric - just look at the MAF voltage at idle and see if it increases with RPM. If it doesn't then it is bad.

[rb101]

I had the same codes about 1 year ago, I replaced the MAF. No codes since.

[geoff]

I had the same codes about 1 year ago, I replaced the MAF. No codes since.

Before you replace the MAF, you could try cleaning it and see if that works for a while. Make sure you use electronic contact cleaner that doesn't leave any residue. If that appears to solve the problem, that's a pretty good indication the MAF needs to be replaced. Note that MAF cleaning is only a temporary solution.

Dharn55 - How many miles on your friend's '00 996? Somewhere in the 40-60K range?

[Dharn55]

The car has about 44K on it. I will try the MAF cleaner I have on his MAF, might do the trick. Thanks for the help.

[996-Sam]

The car has about 44K on it. I will try the MAF cleaner I have on his MAF, might do the trick. Thanks for the help.

Mine is a 2000 C4 with 34K miles. I was also getting P1128 and P1130 every few weeks, so I tried cleaning the MAF and both codes went away for 4+ months now. Defiantly worth trying before replacing the MAF.

[nick49]

MAF is faulty. Save a lot of issues and only go with a Bosch OEM genuine Porsche as aftermaket ones seem to be ok in the short term only to fail in a few weeks. I chased the problem for nearly a year ordering aftermarket ones, sending them back, losing a lot of money and time. Trying other things that would cause the problem finally fit a new OEM and the problem never returned.