I just got back from Auto Zone and they pulled these two codes. Any advice on what this combination normally is. Looks like possible O2 sensor and/or cat issue. I just bought this 996 TT a week ago and it has aftermarket exhaust (not sure what kind), cold air intake, possible chip... Car seems to be running the same - no noticeable performance loss or change etc... Does anyone know what I am looking at here more than likely? Possible cost to fix? Thanks for your input!

 

Nothing to do with the O2 sensors. The primary cause can be your secondary air pump not working. This pump is located in the engine compartment on the right side forward. This pump start when the engine is cold for less than 5 minutes. Did it start? It can also be a leak in all the sense lines on top of the engine. Change over valve malfunction (small gray valve on top of the engine). And finally it can be cause by your diverter valves, malfunction or leaking.... Do a search with your code you will see lots of result.....

 

Clear the codes then drive the car. If the car sat around for sometime this happens.

 

Yep, car starts fine. It did sit around for a couple of month's I would guess. CN this be a possible cause?

 

Thanks for the insight. I disconnected battery and CEL is off. Hope it lasts and I will keep my fingers crossed! Thanks again!

 

When you cold start it tomorrow, listen for the SAI air pump to come on (I think it's on for about 30 seconds). Sounds like a vacuum cleaner. If you hear that, then at least you know you probably don't need a new one of those ($) . I believe the rest of the components in that system are fairly inexpensive.

 

I have the same codes... I do not here my vacuum cleaner running on start up.

 

most likely it is time for new diverter valves or you might have a loose hose that connects to them. I would try replacing those valves first and go from there. Its rare for an air pump to fail and I've only heard of a few cases of a change over valve being needed.

 

If you can get access to a Durametric or PST2 there is a function (drive link) to start this pump manually. Also there is a fuse , maxi fuse 40 amps part# 999 607 011 00, on relay support number 2 which is located behind rear passenger seat. See picture.

 

Very sweet.. I will check that fuse. Hopefully it is that. Sounds like a 92 probility on the fuse... Always check fuses first.

 

Hello,

These CEL codes came back after they were reset a couple of weeks ago. My mechanic said that it could be a few things including but hopefully not likely bad Cats (not sure yet if I have after-market Cats). My '02 tt has 42K miles. What is the likelihood that my Cats are bad? Could it be the car is flashed running a custom exhaust - mods causing these codes to pop up? What usually causes this and what is the fix? There are no drivability issues other than the recurring annoying codes that come up! Your input is greatly appreciated!!!

 

Do you have stock diverter valves? I've had this happen to me (researched a while), and it seems that it's almost always diverters. I have a set waiting to go in now.

 

I actually have Agency Power diverter valves as the ECU has been flashed. Just hoping it's something not too major...

 

Hrm.... now you have me concerned!

 

I got this code and have aftermarket DV's. Turned out that the screw top on one of the DV's had come loose. Tightened it up and solved the problem.