Allen

My Check Engine (CE) light has come ON for the first time since I’ve owned the car (4.5 years) . My car is a ’97 Coupe with 40,000 miles, RSR mufflers, Ruf spoiler module, and nothing else done to the engine. The only “unusual” thing with the car is that yesterday I took it up to about 155mph for about 30 seconds, rode around for another 10 minutes, then turned the car off. Also, I cleaned the engine area last night too. The next time I cranked the car (this morning)...I have the CE light. Question...once the light comes ON for whatever reason; say a connector was pulled loose, then the connector was fixed...does the light have to be reset, or does it go away by itself? Can the O2 sensor(s) be checked easily? Any ideas are appreciated.

jz993

My CEL has come on twice, and gone out on its own within a few days.

Jeff 993TT

My cel light has gone away by itself. Othertimes when I was impatient, I cleared it myself.

Frank 993 C4S

My CEL has gone away twice by itself.

jford

Allen,
I have had the CEL for a couple of different reasons since owning my 96. The firs came with 37k miles on the car, two days after I bought it. I would invest in a reader from Auto Zone or the like, they can be had for about $100 and will not only enable you to reset the code but also help to indentify the cause. My first CEL was for the carbon buildup issue. I reset the CEL but it kept re-occuring. A month or so later I got the CEL for one of the O2 sensors which I replaced. I have not had a CEL since for any reason and have put on about 3k miles since then. I have also run the car fairly hard and done about 7 days of DE (thinking this had helped maybe to thwart the carbon buildup CEL). I hesitate to even type this as I don't want to jinx myself.

You will need to reset the CEL once you remedy any problem causing it. You should know as well that you car will not be ready for emmisions testing unless you complete a rather complicated drive cycle first. I did not know this and failed inspection having reset my CEL just days before I was due. There is a volume of the workshop manuals just dealing with OBDII (some on here have it, i don't) and you may need to reference this to decipher the code as sometimes the explanations the reader gives you don't jive exactley.

Of course, others have had the CEL go off on its own, I have not but for the money I feel the reader is a good investment.

Hope this helps.

Jamie

993944S2

Come September I think, New York State, will require all cars with the CEL light be diagnosed and fixed befor the will pass NYS inspection. New machines are being purchased by shops that will automatiallcy upload the cars codes to a server in Albany. I've been living with the carbon buildup CEL for almost a year. I may not be able to much longer. Bummer.

Don

jford

Don,
New Jersey uses that same system. If you have an OBDII car they just plug in to the port (on the driver side of the center tunnel on our cars) and take the reading. There is no more putting a wand into the tailpipe to measure emmisions as in the past. There are somewhere around 9 or so sytems used for emmisions in our OBDII, if you reset the CEL what will happen is that your system will show NOT READY in most of these areas. I believe that it was designed that way so that people would not reset thier CEL just as they drive up to get inspected. What you can do is to reset the CEL and then go through the drive cycle (it is in the archives, its a pain but it does work) and then check with the reader to see it the systems are ready (this is another great function of the reader, it will show you the readiness of the variuos areas of the OBDII). Of course you would then go right to inspection and hope the CEL does not rear its ugly head before you make it through.

Jamie

ZSA Motorsport

which reader do you guys recommend for reading and resetting codes on the 993TTs?
thx.

csertich

You can get the codes reset and read at an Autozone or other auto parts store for free. Remember to hit the immobilizer button before they hook up the reader.
chuck

Bull

Jamie, NJ has also moved to a program where if the codes do not reset after driving 350 miles after the first Inspection failure, you can fill out an affidavit that says you are not trying to trick the system, etc. and then get a waiver and pass the State Inspection. This is in place for a specific list of vehicles, by year. 1997 Porsches are included, which is why I have a valid sticker. They claim to have found that certain vehicles "never" properly reset the readiness codes.

jimbo3

Why do you have to hit the immobilizer button first? A couple of times, I've simply plugged it in with the engine running and all seems well- is that OK or am I asking for some kind of trouble? (I've had an occasional CEL for a misfire in cylinder 4.)

Jim

csertich

I mentioned the immobilizer because of my own stupidity. I took my car to Autozone and asked them to read the codes. I had turned my car off and they said I didn't have to start it to read the codes. Well, they couldn't read the codes because my immobilizer had set itself. I found out later that if I had de-activated the immobilizer, they could have read the codes with the car off. I just didn't think of it at the time.
I later used some PC software to read the codes and discovered my error. As I recall, the PC software I used said I should read the codes with the car off. ? My memory on this may be incorrect...

chuck

Marv

Allen,

Your real first question should be why. Autozone can read the codes that tripped the CEL. You need to fix the source of the problem.

If you had chest pains, shortness of breath, and a numb left arm, would you be satisfied if the pain just went away?

ZSA Motorsport

whereis the immobilizer button?

Slow Guy

I think they mean the button on the key (fob). Efectivly you're dis-abling the immobilizer.

I failed to do this the first time I connected a reader and couldn't figure out why it wouldn't communicate w/ the reader. I've learned now.