There is actually a lot more to the story. I decided to put my "sticky" tires on the other night to go for some "runs". I remembered that they rub now for some reason. I jack the car up, crank the springs on the PSS-9's a smidge, put the wheels and tires on and drop it down. Looks good, plenty of clearance. Raised the a$$ end 1/2in, that's it. Go for a ride and start to make a run and BAM, all my lights blink on and off and the car bucks like mad, along with what I feel was the loudest backfire I ever heard. I pull over and slow down and everything seems alright...for a minute or 2. Does it again...many times. Pull over, call AAA. I will now omit the boring part. I unplug my MAF and try to drive the car home. I make it, but not after a few more of these episodes. I saw the following warnings on my dash: "ABS/PSM", "Brake Distribution", and a few more I forgot about. I spend most of a night searching these forums for an answer. After some checking on the car, I decide my alternator is bad. Put new alternator in today ($375 and an hours labor) and all is well...sort of.
Go for a spin around the block and BAM...ONLY the "Brake Distribution" under heavy acceleration...almost at redline. Now the question:
Does changing my ride height have anything to do with this? I have run this wheel/tire combo before without issue. The ONLY difference is that I raised the car a 1/2 in. My next plan it too put HRE's and Sumi's back on and go for a ride. Through my search for causes, I have seen bad alternators, dead batteries, broken wiring harnesses, bad ABS modules, bad MAF's and bad speed sensors. Anyone had this issue and resolved it? Scant moments away from having a fire sale...

 

I had a similar problem. The "backfire" was the hose to the DVs splitting open under boost. A few months later, my IC hose on the drivers side did the same thing. I would check for boost leaks first.

Tom

 

Hmmm...interesting. However, I just put my suspension back where it was and put my stock wheels and tires back on and the car is mint?

Oh..and incidently, I cleaned my MAF when I put the new alternator in too, before THIS run and it still had a problem, so I feel it wasn't MAF related. It's the same MAF I have had in my car since I got it over 3 years ago...figured it could use a good cleaning. Didn't notice a difference.

 

I only get that code when I put the biginz on the back with stock sized fronts. Strange in deed. Was there any metal on the wheel speed pickup's?

 

I'm no expert but "The Essential Companion" says that Porsche says that any time suspension work is done, the steering angle sensor must be recalibrated. I think raising the car 1/2" qualifies as suspension work and would explain why your car behaves normally when returned to the original spec. If you have a Durametric, not 100% sure but I believe I read it will do the job.

 

Well...funny you say that, Tim. Here's the story. This tire wheel combo is weird. 2 different brand fronts (don't ask) (although same stock size, but different tread), rears are 305/35/18 Nittos drag radials. NOW, I have run this combo at the drag strip AND at the Texas Mile with no issues. The ONLY difference is: "raised" suspension AND I actually noticed one of the fronts was lower on air than it should have been. In my haste to get out, I neglected to check it. SO, as Larry says, it seems this car DOES NOT LIKE to have any suspension height changes, period.

Oh and nothing else out of the ordinary...like metal on the sensor...