relacing parts, still not fixed

[1boxsterjim]

I tried the cigar trick and seemed to find a leak from the throttle body gasket. Replaced the gasket but still have issue. Took to a shop and had a smoke test, unfortunately it passed with flying colors. One of the mechanics thought he heard an exhaust leak and said the gasket on the manifold to cat sometimes goes, does that sound like a possible solution?

[JFP in PA]

Originally Posted by 1boxsterjim

I tried the cigar trick and seemed to find a leak from the throttle body gasket. Replaced the gasket but still have issue. Took to a shop and had a smoke test, unfortunately it passed with flying colors. One of the mechanics thought he heard an exhaust leak and said the gasket on the manifold to cat sometimes goes, does that sound like a possible solution?

P1126 is on bank 1 normally for:


1. Intake system is leaking
2. Fuel pressure is too low
3. One or more injectors is failing
4. Volume of fuel delivery is low


I would suggest running fuel trims, check fuel pump for correct delivery pressure and volume. I would also pull the plugs on bank 1 looking for one that is sooty or black and wet.

[1boxsterjim]

The fuel trims are in the attachment in the first post

[JFP in PA]

Originally Posted by 1boxsterjim

The fuel trims are in the attachment in the first post

Your short term fuel trims are out of spec by a mile. For example, an "in spec" "long term" FRA trim would be around 1.0 +/- 0.1 and an in spec "idle range" fuel trim would be in the range 0.00 +/- .2. There is definitely a leak issue somewhere, or your fuel system has an issue.....

System description

The adaptation values can be read out with the Porsche System Tester 2.

The key to the adaptation values is as follows:

RKAT = Adaptation in range close to idle

Cylinders 1 - 3

RKAT2 = Adaptation in range close to idle

Cylinders 4 - 6

FRAU = Adaptation in lower load range

Cylinders 1 - 3

FRAU2 = Adaptation in lower load range

Cylinders 4 - 6

FRAO = Adaptation in upper load range

Cylinders 1 - 3

FRAO2 = Adaptation in upper load range

Cylinders 4 - 6

FR = Oxygen sensor for cylinders 1 - 3

FR2 = Oxygen sensor for cylinders 4 - 6

My understanding of range 1 and range 2 is that range 1 is the reading before the DME adapts the mixture and range 2 is after adaption.

[1boxsterjim]

Originally Posted by JFP in PA

Your short term fuel trims are out of spec by a mile. For example, an "in spec" "long term" FRA trim would be around 1.0 +/- 0.1 and an in spec "idle range" fuel trim would be in the range 0.00 +/- .2. There is definitely a leak issue somewhere, or your fuel system has an issue.....

System description

The adaptation values can be read out with the Porsche System Tester 2.

The key to the adaptation values is as follows:

RKAT = Adaptation in range close to idle

Cylinders 1 - 3

RKAT2 = Adaptation in range close to idle

Cylinders 4 - 6

FRAU = Adaptation in lower load range

Cylinders 1 - 3

FRAU2 = Adaptation in lower load range

Cylinders 4 - 6

FRAO = Adaptation in upper load range

Cylinders 1 - 3

FRAO2 = Adaptation in upper load range

Cylinders 4 - 6

FR = Oxygen sensor for cylinders 1 - 3

FR2 = Oxygen sensor for cylinders 4 - 6

My understanding of range 1 and range 2 is that range 1 is the reading before the DME adapts the mixture and range 2 is after adaption.

It would appear my efforts have paid off. I believe replacing the gasket on the throttle body sealed it. A smoke test revealed that there was no vacuum leak and taking to a well know Porsche garage validated the numbers are good. Thanks everyone for reviewing my information and providing analysis/suggestions. Jim