Received the following P codes on my 01 Boxster S “PP1130 and PP1128” Does anyone know what they mean? I cleaned the MAF thinking that may be the problem, cleared the error codes and drove 158 miles and the check engine light came back on with the same codes. Help Please... any suggestions?

 

I think they indicate a lean condition on both cylinder banks (as read by the 02 sensors) that the computer is unable to correct. It is frequently the MAF, so you may need to replace since you've already cleaned it.
It could also be an air leak or a bad air Oil separator, but those are far less common than MAF issues
Good luck
Randy

 

Have you removed or replaced your muffler recently?

 

Chuck,
No work on the muffler, the car only has 21k miles.

 

so AOS problems not as uncommon as MAF. And delayed recognition of failing AOS subjects engine to some risk of severe damage if car continued to be used.

Sincerely,

Macster.

 

remove cap. If you are able to remove this is not confirmation AOS *not* bad.

However, if you can't remove cap this a symptom from one of my car's two AOS failures.

Be sure to install cap and while you're there check cap does not leak air. My car's cap developed a leak and symptoms fooled me into replacing a perfectly good MAF when a $13 cap was all that was required.

If you have OBD code reader/data viewer you can disconnect MAF from wiring harness, leaving MAF installed in intake tube. Clear codes and then monitor long term fuel trims to see if engine controller is still having to add fuel (readings going up from 0) or having to remove fuel (readings going negative, below 0). Readings of +/- 10 or higher are generally indicative of something amiss.

Also, check short term fuel trims. Looked at car with suspected MAF and even immediately after clearing error codes -- which also sets long term fuel trims back to 0 -- and not only did long term fuel trims show -10 or lower but short term fuel trims were bouncing around +15 to +18. Quite abnormal readings based on my experience clearing codes and monitoring long/short fuel trims immediately after.

If readings look normal drive car and continue to monitor fuel trims. If trims maintain normal levels and engine runs wtih no symptoms MAF becomes prime suspect.

Sincerely,

Macster.