Wanted to see if anyone else has has this issue with their 996tt.

I took delivery of the car Friday, had it taken apart to install speedtech exhaust on Sunday. When I went to start it on Tuesday, it had a very erradic idle, which I attributed to the new exhaust. The problem is that it got better but never went away. At stop signs, the car acts like it's going to stall when I accelerate- then bucks to life and drives fine.

I have a 996 NA that I drive back to back and it is accelerating to 10mph Much smoother than the turbo. I am getting cel codes p0159 and p0139, both 2ndary cat codes that I attribute to the mufflers and blow off.

Do I need to flash the car for this exhaus setup already just to get her to drive normal?

 

Sorry about the thread title, my fat fingers can type on the phone. I'll see if a moderator can alter it

 

fixed

 

what kind of exhaust, with cats or without ?!

 

Speed tech 70mm with cats. I expected the cel with the high flow cats, but the driving behavior is what bothers me

 

Make sure you put the right o2 sensors back in the right spot..it DOES matter. The front and rear o2's are different.

 

good tip, thanks !

 

Same thing happen to me when I changed to EP st2. I unplugged battery for 15 mins. and it ran perfect afterwards? Read article on this forum and it worked for me? Resets computer??

 

not only must co2 sensers be in the correct place, but "bungs" may be necessary to eliminate CEL. Speedtech will provide these at NC, at least they did for me, and cured the issue...

 

Yes. Sometimes aftermarket cats are a little too unrestricted and the ECU has a problem getting used to them.

 

NOLA,

What you are describig is not normal for our exhaust. We have installed so many of these systems without issue.

I think you have something else going on, but maybe as some have said, the car requires some sort of ECU adjustment, although I personally have never seen this before...normally you install the exhaust and the car runs better.

First thing I would check is the 02 sensors for a cross install (fronts in the rear and vice versa) and you may as well disconnect the battery and try that, too.

 

Thanks guys, No mixup on the 02s. I installed them myself and marked the wires for each.

I just took it for another spirited run and got PSM and ABS failure flash accross the screen. It died in traffic at no MPH.

I think it's not an exhaust issue, just happens to be occuring the same time. Any recommendations outside the o2 sensors?

 

When did you last change the MAF? - try a spare or swap with a buddy.

Jim

 

Either o2's are bad now (it happens when you mess with something that works!) or, as was said, try a new MAF.

 

Would the MAF from a 996 NA work on the turbo?

Dont really know anyone else around to swap with. The car is undrivbeable now. I checked all boost hoses with no problems.

Even if the 02 sensors are bad, the codes are reading 2ndary 02s are bad.. which shouldnt have any affect on driveability, right? They should just be a warning that the cars emmissions are not up to par. The speedtech I bought used from a member here has the extension bungs installed already