Okay guys,
My 2001 TT has started to do a really weird thing...after driving for a while, usually when idling, suddenly I get a CEL light for BOTH ABS failure and PSM. Then, the engine starts to idle funny...kinda revs up and down, almost wants to stall, then revs back up again. This has happened 3 times now and I'm starting to get worried. It never starts upon start up and only after driving for a while...do you guys think my extended warranty would cover any problems? Do you think flashing the ECU to either PSI or GIAC would solve this problem? Any opinions would be appreciated!

 

Check for a loose boost hose. That can trigger the CEL and ABS lights and cause idle problems.

 

Def. get it fixed BEFORE any ECM work is to be done, you need to get this car running perfect first. Check your hoses as indicated in above post and also check your MAF sensor as well. That sounds like a typical Mass Air Flow sensor problem from what I have seen here on this board. Best way is to scan the ECM and see what kind of trouble code(s) you are getting before any repairs are done, it will save you a bunch of time.
And yes I think your aftermarket warranty should cover it, take it in to Porsche and get it checked out.

Bajo

 

Most likely a dirty MAF. Try clean the MAF first. Where are you located?

 

A "dirty" MAF typically won't throw the ABS/PSM lights. Unplugging the MAF does that (try it and you'll see). A dirty MAF will cause fuel trim issues, but typically won't throw the ABS/PSM lights. It will, however, typically throw a CEL (anywhere from the "air flow sensor" CEL to the "fuel trim too rich" CEL). Of course, if the MAF is dirty enough the ABS/PSM could be tripped, but not likely.

My opinion (as I agree with the previous suggestions): the MAF is on its way out and/or loose boost hoses. A leak in the boost/vacuum system will obviously cause idle issues, but so will a MAF that is going/is out. My hunch is that it is the MAF.

 

sounds like an excuse to chip your TT

Check your MAF and hoses, wait till it runing perfect to do the flash!

 

Thanks for the great suggestions and responses! Yeah, I guess I am just looking for an excuse to chip my TT!

 

the idle hunting definately sounds like a vacuum leak to me.

 

Okay, a further update...the lights don't come on upon initial start-up. I drive it a while, everything is fine, but when I leave the car in idle, like to cool it down after a drive, that is when the lights eventually come on. So, do you guys still think this is a vacuum leak or loose hoses when the lights come on after the car has been driven and put into idle? The mystery continues...

 

Simply have the ECU read with the PST2 and it will show pending. I have seen MAFs on stock cars do some funky things and it is not always a steady code. There will be one pending though that can be read.

 

So, it trips the code at idle after a hard drive? I'll take a guess on this one (again) since I had roughly the same issue at one point in time with my car (I did not throw the ABS/PSM lights, but as you know, they are linked to a failing MAF).

I am going to guess that you throw one or both of the below codes:
P0175 OBDII Trouble Code - System Too Rich (Bank 2)
P0172 OBDII Trouble Code - System Too Rich (Bank 1)

If that is the case, then it is your MAF, I am rather positive.

 

Just to offer some contra-evidence, I have been seeing these two codes (P0175 and P0172) for some time now (two months running?), and we have replaced the MAF twice, most recently last week, and the problem persists. It always throws the codes at idle, and PST2 confirms that it is reading too rich mix at idle (correct my memory if I'm wrong, Alex). However, this is on a GT640 car, and the current suspect is on the fuel pressure regulator that comes with the kit. Anyway, just wanted to add another scenario in which you could see these codes.

 

It could be that as well. I have datalogs to prove my case, but I also have stock ECU as does the original poster. Mine was a bit more simple and had less variables. I was working off of the stock A/R ratio mappings. You might want to run a voltage test on the MAF and take a look at the A/F ratio mappings for your ECU's new settings. My guess is that if that is the case, then perhaps the mappings aren't set for the FPR correctly.

 

Ahh the benefit of the search function.

I have the exact same problem as this and it is triggered once the car reaches a certain temperature.

My dealer has diagnosed the MAF failing at higher temperatures, does this mean it's going to fail soon or can i CLEAN IT AND HOPE FOR THE BEST?

 

Check boost hoses for tight fit.