On my 2000 Carrera 2 cab. I just got it back from the dealer after having one of the cat converters replaced with a new unit due to a Check Engine Light notification (paid by the seller), and a pre purchase inspection. They cleared the CEL, and it received a clean bill of health on the PPI, so I purchased it. They returned the car to me with very little gas in it. I drove it 10 miles back from the dealer and loaded it on the trailer for the journey home. Upon arrival, I added 2 gallons of unleaded regular (I realize premium is required) to the tank to be sure I would make it to the gas station. Upon it's next outing and driving very gently while heading to the gas station, after 5 miles the Check Engine Light reappeared. I checked items such as gas cap and oil cap being on tightly. I checked the oil level. All were correct. Any ideas as to why the CEL so soon after the cat was replaced? Should I try to disconnect the battery (I have an aftermarket stereo system installed) to try and clear the light? Could the regular unleaded in a cold car have any effect due to insufficient octane rating? There was no manual delivered with the car, so I am awaiting delivery from previous owner. Any help would be greatly appreciated. Thanks.

 

Run the codes. If you dont have an OBDII reader, drop by autozone or such and they'll run the codes for you.

 

Thanks geetee. Can the Autozone type of OBD2 reader also clear the Check Engine Light?

 

Yes they can clear the code.

 

might be an o2 sensor is needed on the new cat.... get the code and that'll give you a hint..

 

Thanks Mike, I have a code reader on the way. I appreciate the help. If it is indeed an oxygen sensor, are these standard Bosch units, or do they need to be purchased from the Porsche dealership? In your opinion where is the best place to buy parts? Thanks again.

 

I'm sure there are cheaper one's but check pelican parts or maxspeed or rockauto...roughly around 100 for one. You've got 4 of em.

 

Thanks again geetee. Are the before and after O2 sensors the same, or different part numbers? I will look up the names you suggest. I really appreciate the help. Jim

 

I'm not sure if they are actually different and interchangable between years but before and after have different part numbers 99, 00-01, 02-04 all have different part numbers also.
edit: some places list 99-01 with same part numbers

 

I have the same check engine light, how was this resolved? Did o2 sensor replacement work? _ thanks!!

 

I had several CELs in the past. Every time it appeared, I had it reset. Then I had a couple of O2 sensors changed based on the codes. CEL disappeared for a few days. Then CEL appeared again and despite clearing it out several times, it always came back on after a day. I got tired of it and left it as it is. After 3 weeks of leaving the CEL on without resetting, it mysteriously disappeared. A couple of weeks had already passed and it never reappeared again. Knock wood.

 

The CEL was resolved by MY discovering that the tech at the $180/hr Porsche dealership had installed the pre and post cat O2 sensors in the wrong positions. In other words, the pre cat sensor in the post cat position, and vis versa. Amazing.

 

a loose gas cap can trip CEL, ask me how I know, and I thought that may have been the culprit so removing the neg battery cable for a few mins shut it off never to return....if it's an O2 sensor it'll light up again upon driving it. Try that

 

By the way what code reader do most guys use here, I've seen sveral for less than $100.

 

I believe most use Durametric...

durametric.com