Engine Check Light: P1128 & 1130

[blue62]

Originally Posted by Jonconsean

Hi,

I have a 2000 Boxster and I am having issues with the check Engine Light coming on. I am pulling the p1128 code and p1130 code. So have been reading forums and I have cleaned the MAF sensor and Throttle body and rest the codes. They come on after driving. Confirmed the Oil caps and gas caps are closed and the codes come back. I have replaced the MAF sensor and Oil filter , reset the codes and they still come on.

I took it to my Porsche repair guy and after a 10 min ($100) diagnostic , he said the MAF sensor is bad. I told I bought it new at Autozone. He said that it was either faulty or I didn't reset it right (which I think I did). He is charging me $400 for a new MAF sensor.

Does anyone have any advice/ suggestions. I am a little frustrated. Thanks for your help.

those codes refer to a short to battery positive on both of your post cat O2 sensors.
since it is both sensors with the same problem I would look for any fuse or relay that would affect O2 sensor function.
Then I would test the sensors
then look for a wiring issue
then look to a bad DME

[78F350]

I think the info in this post on Renntech is more accurate:
https://www.renntech.org/topic/32802-error-codes-p1128-and-p1130/

Lean condition detected by the primary O2 sensors that cannot be corrected by the DME.
Think: Too much air, or not enough fuel, or sensors on either end (MAF or O2) are reading incorrectly.

and here's a pic that was posted on Rennlist:


...not that I'm particularly smart on this, but I've been dealing with it intermittently over the last month on one of my cars.

[blue62]

[QUOTE=78F350;600925]I think the info in this post on Renntech is more accurate:
https://www.renntech.org/topic/32802-error-codes-p1128-and-p1130/

Lean condition detected by the primary O2 sensors that cannot be corrected by the DME.
Think: Too much air, or not enough fuel, or sensors on either end (MAF or O2) are reading incorrectly.

and here's a pic that was posted on Rennlist:


...not that I'm particularly smart on this, but I've been dealing with it intermittently over the last month on one of my cars.[/QU


I just looked up the codes in the Bentley manual and relayed them in my post. With the Bentley saying "short to battery positive" I would still check the things I listed in my post to the OP. If all was ok I would then look to the to much air not enough fuel scenario. As the Bentley states the system is calling for enrichment beyond the upper limits of the system. Vacuum test for excess air in the intake. exhaust leaks ahead of the O2 sensors. If all ok then on to fuel issues.