Just bought a 2003 4S 13 days ago. 33k miles on it. On day 3 of owning both the ABS and PSM warning lights come on. Next morning the lights are off on start up. The lights come back on periodically and go off when car is off and sits for awhile. I take it back to place I bought it from and they tell me it's a brake sensor or switch. No big deal I'm told. They order the part and I return there three days later. Lights were off and on during this time. They change the part and tell me it's solved. I leave and notice the engine sounds different to me. Later that day the engine seems to lug or momentarily lose power in second gear around the 3k rpm range. I'm able to power through it and it doesn't happen all the time. This continues to happen over next three days. Then the warning lights come back on. Later that day, I turn the car off and pull the key, and it is still running and a airbag failure light comes on. I put the key back in and turn forward and back and it shuts off. Restart and can't replicate. Drive it to see if this new warning light will come on and car lugs/drags in first gear, can't go over 15 mph for about a block before it breaks through. Engine sounds even more different. Later, I shut the car off and the airbag failure light comes back on with the car still running after the key is pulled. This time I don't out the key back in, I press the brake pedal and it stops. I've wanted a Porsche since I was a kid. This was supposed to be a wonderful experience and it's officially a nightmare. The place I bought it from is arguing with me over it. What is going on with my car???

 

You should consider taking it to a trusted independent Porsche mechanic in your area. There's no need to keep going back to whoever sold you the car as they are going to be as cheap as possible.

Good luck.

 

The lugging sounds like dirty fuel injectors. ABS sounds like a bad sensor possible at the wheel or a short. Check your pads and rotors.

 

What state did you buy it from? Do they have a 30day money back guarantee or anything?

Did you check carfax before buying it?

I hope it wasn't one of those flooded cars as it can be a nightmare to track down electrical issues.

I would first get any codes pulled. Maybe try CRC MAF cleaner and clean out your MAF since it appears to be happening in only certain range.

As for the abs lights, I wonder if the dealership cheaped it out and just tried cleaning your speed sensor(s) instead of actually replacing them? You need to have it scanned to make sure if the computer is bad(unlikely) and to know which wheel speed sensor is faulty.

Good Luck.

 

Sounds like the ignition switch needs to be changed. Keep us posted.

 

Same happen to my old 996, both ABS & PSM lights come on & off intermittently. It turns out to be a bad "accelerator position sensor". I think I got raped cause they charged me $650 for the part. (part# 996 606 115 00)
You should get it scan as mentioned to find what's causing all the problems.

 

Check your battery voltage and connections. When low voltage runs through the system ( either by dying battery or intermittent connections) it plays crazy on the brake system warning lights. I went through this myself and found a loose body ground which cleared up both od these symptoms you've listed.

 

I know it is a little late, but when you are paying that much for a car, a PPI is a must!!!! Otherwise, you end up taking the car back and they keep telling you there is nothing wrong. There are thousands of 996s out there without issues, and either you got a bad one or the seller is less than honest. Good luck and don't blame Porsche

 

Sounds like the ignition switch steering lock assembly is bad and you may have a fuel pump that's on its way out. One of the most common electrical items to fail on some of the older Porsches is the ignition switch. This failure can show up in any number of ways. The car can refuse to start some of the time, the key may not turn too easily in the ignition, or strange electrical problems may appear. Here is a DIY for the replacement of the switch. It's always good to check the basics first so definitely check the condition of your battery and charging system as well.

 

You can use the Audi part that is like $8 for the ignition switch off amazon. Just get some stubby screw bit set to do the install. Search for how-to in forum.

http://www.gagme.com/greg/996/ignition