Good Q&A on Engine Codes P1128 & P1130

I saw this good Q&A today, and thought I would post it here for someone's future reference if doing a code search.

Here it is:


QUESTION:

DME indicated air/fuel mixture problem.
This came on after I ran Syntech feul injector cleaner.
I changed my fuel filter since and the engine light went off then came back on within 15 miles.
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I talked with someone who had a problem with another car but syntech cleaner & they had to replace their oxygen sensor.
Any suggestions?
Thank you

ANSWER:

These faults are do the system has reached its maximum threshold to compensate for a lean system. This can be caused by either a bad or dirty MAF sensor in which you can clean or replace. Perhaps an intake leak in which would most likely be at the oil separator bellows. The last and not as common problem would be low fuel pressure or dirty injectors. I would get some good quality electronics cleaner and clean the MAF first. After that then you can get under the car and check the oil separator bellows for deterioration.
Scott Slauson - PCA WebSite - 2/12/2006