Turboflyer

Just had a check engine light indicating P1128 O2 sensor Range 2 for both 1-3 and 4-6 cylinders. No where can I find which set would be range 2. I would think logically, they would be the ones after the converters. Can anyone help me pin point which set is range 2. Or, should I just replace all four at the same time, 52,000 miles. Do I need factory ones, or will any OEM type work? Thanks

keoni986

I have gone your route with the same CEL code and it turned into another one, P1130. Changed the O2 sensor twice and still had the codes. It has to be the MAF.

Keoni986

originalmotorhead

my suggestion is to remove the MAF sensor and spray it down with brake cleaner, then dry it off with compressed air. I had the exact same codes and cleaned my MAF sensor and fixed the problem.

I have a scan tool that also displays real time the data off of each sensor and after I cleaned the MAF sensor, the readings were higher.

tom

Turboflyer

I will certainly give it a try. And I failed to mention that I had both the 1128 and 1130 02 range 2 banks 1-3 4-6 readings. I talked to a very knowledgeable Porsche mechanic and he said basically the same thing. THe MAF sensor can go bad and the 02 sensors go out of range trying to correct. I just wounder why there is no MAF sensor fault reading. Well, certailnly worth a try.

PTEC

90 percent of the time, when we talk about MAF sensor failures, its not that the sensor actually fails. Its still fully functional but what happens is contamination causes the sensor to read incorrectly. The DME will inject fuel according the to incorrect air reading. This will cause the mixture to be off and the o2 sensors will see this and tell the DME to adapt the injection time to get the mixture closer to lamba. The DME can only adapt so far before it throws a fault and thats where all these oxygen sensing faults come from.

blinkwatt

Anyone here up for a group buy of MAFs?

Turboflyer

Turns out it was the air/oil seperator putting to much oil into the mixture. No CEL since replacement.