1999 Porsche Carrera 996 idle issues

[alirza_e]

Hello

I recently purchased a '99 carrera C2 through a private party. The car is in showroom condition and I had it preinspected at Porsche w good results and installed the newer LN Engineering Bearing and at the same time they installed a new cluch and oil seal for around $2800. So i felt much more confident about the car as a preventative measure for the engine failures they are prone to, I was driving it about 5 days ago (2nd time driving it since purchased) and while I was on the highway doing about 75miles an hour, I exited and took it out of gear and placed it in neutral as soon as i did that all the instrument control lights came on and the RPM fell down to 0 and the engine turned off and when I placed it back into gear again the car's engine came back alive again. The instrument cluster lights disappeared after a few secs. I was able to duplicate this problem over and over again by ramping up the speed which ramped up the RPM's and putting it into neutral and same thing happened again. I took it to my Mechanic and so far he is thinking that its the idle controller but he is suppose to get back to me again tomorrow. The mechanic already replaced the idle controller and he told me that the computer does not correspond w the new idle controller and he asked me to bring back the original air intake and I did. This car has an aftermarket K&M air-intake. I don't know if its the sensor for the air flow thats not working or what? But again he is suppose to call me tomorrow and let me know if swapping the airintakes w the original got it fixed or not. Meanwhile if anyone has seen this problem or has any suggestions please feel free to drop a line as any hints and clues are appreciated. Thank you for reading such a long essay but I just wanted to be as clear as possible. This is a great car but I am pretty disappointed about all the flaws that we have to deal with. It makes me nervous driving it everytime as I work hard for my money. Just saying

[BYprodriver]

First thing I would do is clean the throttle body & MAF (mass air sensor) then disconnect the battery for at least 20 minutes so the Computer can re learn your driving style. The air cleaner is not your problem, a mechanic that dosen't know 996's is.

[alirza_e]

Thanks for the reply Byprodriver.
Are you sure that I can just clean the items you listed the throttle body and MAF and disconnect the battery. Below is the results that my mechanic gave me. He tried the old idle controller w the original air intake and the car engine still shut down at higher rpm's. So he replaced it w a new one w my original air-intake and it was fine.

Apparently the aftermarket K&M air intake does not have enough back pressure and way too much air flows in which screwed up the idle flow controller unit and had to replace it w a new one and put back the original air intake. The car is not dying anymore after higher rpm's. Apparently K&M has become aware of this issue and are trying to resolve the issue. Meanwhile I just got the car and had to fork over another 700 bones for no reason which took away from my audio system budget. I am pretty pissed about it. I am going to call K&M and see if I can get some kind of credit fot their faulty product which damaged the car.

Does anyone have other aftermarket brand air-intakes installed on their cars which has not given them any problems. If yes can you please give me the brand name so that I can research it as I like the sound and more power it gives the car.

[BYprodriver]

Originally Posted by alirza_e

Thanks for the reply Byprodriver.
Are you sure that I can just clean the items you listed the throttle body and MAF and disconnect the battery. Below is the results that my mechanic gave me. He tried the old idle controller w the original air intake and the car engine still shut down at higher rpm's. So he replaced it w a new one w my original air-intake and it was fine.

Apparently the aftermarket K&M air intake does not have enough back pressure and way too much air flows in which screwed up the idle flow controller unit and had to replace it w a new one and put back the original air intake. The car is not dying anymore after higher rpm's. Apparently K&M has become aware of this issue and are trying to resolve the issue. Meanwhile I just got the car and had to fork over another 700 bones for no reason which took away from my audio system budget. I am pretty pissed about it. I am going to call K&M and see if I can get some kind of credit fot their faulty product which damaged the car.

Does anyone have other aftermarket brand air-intakes installed on their cars which has not given them any problems. If yes can you please give me the brand name so that I can research it as I like the sound and more power it gives the car.

Cleaning the MAF & T/B with spray cleaners made for this is the first thing I would do to see if that is a problem. If the K&N filter has too much oil on it it can get on the MAF & ruin it, but the engine sucks the air it wants thru the filter. Call K&N & ask their advice about your issue.

[Wheel Dynamics]

Originally Posted by BYprodriver

Cleaning the MAF & T/B with spray cleaners made for this is the first thing I would do to see if that is a problem. If the K&N filter has too much oil on it it can get on the MAF & ruin it, but the engine sucks the air it wants thru the filter. Call K&N & ask their advice about your issue.

Just as a side note, cleaning the MAF sensor only works a fraction of the time, once the oil is introduced it's hard to say if the sensor can be saved...

[dmorgan]

I had a similar issue on a 99' 996 after switching to a Fabspeed intake system. It turned out it was the coil boots sparking erratically due to cracks. It was a cheap fix to replace all the boots.

D