Just to make things clearer for you....the fuel trims you showed do not, by themselves indicate that an O2 sensor is bad. I am not doubting that your Bank 1 O2 primary is bad due to the error you are getting, but the STFT you reported are normal. These readings should be bouncing around between negative and positive whenever the engine is running. Their purpose is to try to maintain a perfect F/A ratio as dictated by the computer.

You should be able to look at the O2 sensor readings directly with your scanner and both the primary sensors should be switching quickly and continuously between low voltatge and high voltage. The graph of O2-1 probably will show that it is lazy and is not switching voltages as quickly or low/or high enough.

LTFT does not need to be at or even near zero for the engine to run properly. Many cars will have long term fuel trim readings of +/- 10% and this is normal. LTFT can go -25% before a code will be generated and +20% without a code. The 2 banks do not even have to be close in the LTFT reading. You may have 1 injector that flows a little better than the other 5 and the LTFT on this bank will show a larger negative fuel trim than the other bank. This is normal and the computer is doing what is is supposed to do. In my car, there is a 8 percetage point difference between bank 1 and bank 2.

Get to know what your normal readings are of your sensors and it will make future diagnosis easier.

 

MAF's go bad. Period. Sometimes it deteriorates over time, other
times will fail without warning. Just like some peoples logic.
I have been on both sides of the equation, VW/Audi has had trouble with maf's since day one. Before you say a word, it has everything to do with what you are complaining about. All 3 companies (P, VW/A) use bosch motronics and mafs. They have been wrestling with this for a long time, and VW came out with a more durable, and less expensive replacement. The failure of these were blamed on substrate/lamination failure and was pretty common, Porsche failures seem to be less prevailant, maybe because there were less produced. Having said all that, increased air flow, or a cone filter isnt the decisive factor. Actually the word you should use instead of corelation, would be coincidence.

 

To determine the condition of a MAF, it should be checked under full load in a high gear, with consumers switched off. Two parameters
you should be concerned with are air flow in grams per second, and your load calculation factor , in %, ( or its Porsche equivelant ) and compare it to a known good car. Both of these values are a direct function of the maf"s airflow measurements.

 

O2 sensor was replaced yesterday. HELLO HP! WOW what a difference. No dumping boost. I feel like a kid in a candy shop!

Now if only the 700 bits would show up....