Need Help: CEL Again! - Page 2 - 6SpeedOnline - Porsche Forum and Luxury Car Resource

#16

07-12-2011 | 11:32 AM

Frank ( Sunnyside )

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Quote:

Originally Posted by Bux996tt

Okay, just got back from the shop. Codes this time are P1126 and P1133, both o2 sensing lower range. Reset the codes. Car sputtered for about a mile, probably due to having the codes cleared. I am not confident they won't return, just doesn't seem to be running great. Did run smoothly with tech in the car up to 1.0 bar but somewhat erratic for me later.
Comments....

Hi,
TBH I find the code P1126 a bit confusing.
When you look them up on the POSES system its says:
P1126

356 Oxygen Sensing Adaptation, Lower Load Range,

Bank 1 - Below Limit
And:

356 Oxygen Sensing Adaptation, Lower Load Range,

Bank 1 - Above Limit.
I'm not sure which it is with your code P1126

I understand the reasons for both and can visualised the test procedures for both. I cant understand how from one code P1126 you can get either a 356 "Below Limit" and a 356 "Above Limit"
Its also the same with P1133 which is the same fault for Bank 2, with the same Above and also below limit.

Anybody know how you are suppose to know from the code which it is supposed to be?? Never having seen that code come up on PST2 (yet) I can only assume that the diagnostic readout will tell you exactly if its above or below limit??

Either way its saying if the fault is below limit you getting too much fuel
Possible cause:
Incorrect signal from MAF sensor
Fuel pressure too high
Fuel injector leaking

The Above limit is the opposite and saying that the mixture is too weak possible cause:
Incorrect signal from MAF sensor
Intake air system leaking
Fuel pressure too low
Volume supply of fuel pump too low

Fuel injectors fouled

Same idea for 1133 Bank 2.

If its not your MAF perhaps its your fuel pressure/pump .

I wouldn't think you have an injector problem as both banks are showing problems which tends to lead me to think its something common, like fuel pump not producing the full pressure. I would have the pump removed and check for the common fuel pipe splitting fault.
ie there is a pipe on the pump that is in a C shape and splits very often. If yours is just starting you could be getting low fuel pressure.

This is all assuming you have done as Markski has suggested and done a boost leak test, as that would cause a weak mixture as well. Please tell us you have done a boost leak test.!!!

Get a fuel pressure test done on the car if you don't want to lift the pump out, although the more I think on it the more plausible a split becomes. My Car is off the road getting bigger turbos etc etc etc and is having the fuel pipe changed just to be safe.

Last edited by Frank ( Sunnyside ); 07-12-2011 at 12:02 PM.

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