Cel P1128 P1130

[MNBoxster]

Originally Posted by no_substitute

CEL came on yesterday while driving my 2000 Boxster S with 23,500K miles. I did replace the air filter about 100 miles ago with a stock Porsche air filter. Checked codes at Autozone, came P1128 and P1130. Any advice before taking it to the blood sucking dealer?

Hi,

Pcode 1128 - Oxygen Sensing adaptation, idle range, Cyl. 1-3
2 possible explanations:
Short to Ground /below Lower limit/lean mixture threshold
Short to B+/above Upper limit/rich mixture threshold

Pcode 1130 - Oxygen Sensing adaptation, idle range, Cyl. 4-6
2 possible explanations:
Short to Ground /below Lower limit/lean mixture threshold
Short to B+/above Upper limit/rich mixture threshold

These indicate that the O² Sensors are signalling Above/Below the programmed mixture thresholds and the DME doesn't know what to do. It could be the O² Sensors, but I doubt it since it's coming from both Cyl. banks.

As I suspected (I caught your post on Autobahn(Flat-6)), I think it's the MAF. Several people here have seen the same codes when their MAF was bad. It's possible that when changing the filter, some dirt was dislodged and has now contaminated the MAF, or that the increased airflow from the new, unclogged, filter is causing the MAF to send the wrong signal and therefore the O² Sensors are seeing too much/too little O² for the amount of AF being burned.

You can try removing the MAF and cleaning it, most have good luck with this. CDC makes a spray MAF cleaner avail. at most Auto Stores. Good Luck! Hope this helps...

Happy Motoring!... Jim'99