Check engine light on: FINAL STATUS 6/14

I have a 1999 996 with 14,500 miles. I just had my 15,000 miles service done. For the first time, my "check engine" light came on. I checked the oil, water and possibly loose filler caps (as per the manual) and everything is good. The light is still on. Oil pressure and engine temperature is good. I drove by an independant repair shop this morning and the office guy told me that this is not uncommon and sometimes simply disconnecting the battery for 10 minutes might fix the problem. It's under warranty and I'm tempted to hold off until I can get an appt. with the dealer. Comments are welcome. Thanks. Carl (New member)

I was at my local dealer yesterday and someone stopped by with the same issue - what I heard was that it's usually caused by the gas cap not being closed tight enough. I beleive the dealer told the guy to turn the car off, tighten the gas cap fully and turn the car back on. Wasn't sure if your in the same circumstance or not - the first question they asked was that if he had just put gas in the car. T2

I had a similar problem once, but not on a porsche. It was an 02 Sensor. Apparently, the senor somehow regulates the air in the exhaust and when it gets out of balance the check engine light comes on. So, it can just be an emissons problem; nothing really serious expcept it might affect your gas mileage. Best to go to the dealer. They have to hook it up to there testing gizmo to tell for sure.

had the same problem with my my99 996 cab tip.the usual advise fm dealer was fuel cap.happen to me three times already,going back to the dealer tommorrow.hope the lite remians litted,as everytime a day before my schedule visit to the dealership,it somehow goes off!other than the irratable warning lite,have been driving it with no problems.

My dealer has actually loosened my cap TWICE on me. I caught him the second time around. Kind of "funny" how your light goes on 50 miles after driving it away from the dealership.....

Any knowledgeable independent shop can read, repair and reset the stored fault codes associated with check engine lamps. A generic OBD II scan tool is all that's needed. Most common failures are loose or leaky gas caps triggering EVAP codes. It sometimes takes several open to closed loop drive cycles for it to reset failures on its own after the problem has been corrected.

Just got mine turned ON! So, going to try the usual things. Gas Cap, Check Oil, Coolent, and finally the disconnecting the battery. But, I think it is the Fabspeed Airbox and the BME filter. Kinda odd since I had it for over 5k before this happened.

Happened to me about a month ago. The porsche dealer replaced a sensor of some kind under warrentee. He said they are extremely sensitive. It is not uncommon.

Would changing the airbox and the filter change warrenty? Just curious. Maybe I put the stock crap back on before heading in for service.

bloke: I have always heard it would be necessary for the dealer to prove the mod caused the problem. For example, if you have an aftermarket intake and you go for warranty service with a leaky rear seal - no problem. However, if you have the same aftermarket intake and go for warranty service with water in the engine - big problem. Seems logical to me.

I found the following on a different discussion where the question was "Should I buy a 1999 996? ....Early MY '99 cars had some reported (i) engine warning lights associated with failing to replace the gas tank cover properly following filling up at the pump..... We'll see if this case when I take it in on 6/14 for warranty service. I go off warranty on 04/03.

Hi Carl, Ive had my VERY EARLY 99 996 C2 coupe for about 6 months now. It has 42K miles. Since I got it the check engine ligh has been on and off constantly. It is the oxygen sensors. The car is running WAY rich and I go through gas like no tommorow. The car is out of warranty. Dealer (Ira Porsche in Danvers, MA....I work there) will fix the problem under Porsche good will. They will replace 2 of the 4 oxygen sensors first, then if that does not do it the other 2. Other than that the 996 is AWESOME and totally eclipses the 993 in every aspect. Good Luck....

Darn this stuff is scaring me and I did a few mods already and no check engine lite(cross my fingers/toes/eyes). How would one know if the check engine lite in my car is broken? Regards. Mike

check engine lite-got my car back fm the dealership replace the o2 sensor n so far the lite has not appear,yet.

If it is not the gas cap thing it is the 02 senors. An emissions problem that affects your gas mileage. It is all about air and should be covered if you are under warranty. If not, you are looking at $300-$500. <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

Mine went on due to a faulty MAF sensor before installing the intake. No other problems since.

Just got it back from the dealer. It was in fact the Mass Air Flow sensor. The service technician explained to me that it sensed something wrong in the speed, volume and/or density of the air and tripped the "Check Engine" light. I asked him how much it would cost if it was not under warranty. Answer: $450 for the part and 2 hours labor @ $85/hr. He also said that he thought this part was warrantied for 5 years vs 4 years for the rest of the car.

Congrats and happy motoring.

You don't need to dealer to change the MAF. Actually, when you change the intake to something like a Fabpseed you actually need to remove the MAF and re-install. Anybody with a phillips screwdriver can change the MAF in 15 minutes. FWIW...