My 06S just got the check engine light lit on the tach. I have no other warnings and no messages on the osd. Car runs great.
We had a gas shortage after Hurricane Sandy, and my wife added a half tank of regular to the half tank of super in the car. Only fuel available.
I added 1/4 tank of Super this morning, Light is still lit. Gas cap is tight.
This happened when temp. outside hit 34 degrees for the first time this year. I may have the original battery, not sure if original owner changed it. No other problems at all. I expected more Gremlins if the battery was bad.
Wife said car beeped and headlights did not go off in auto mode?
Can't check codes, want to stay away from the stealership.

Could this just be a routine maintenance light?

 

No, even a full tank of regular is not going to light the Check Engine" light. The engine management system will re-map for the fuel and you won't have the "premium" performance but it shouldn't light the CE light.

More than likely another issue like failure to seat the fuel cap correctly is the issue.
Maybe Dennis' wife can give a class on that????

 

You'll need to be able to pull codes to know what's going on. Any generic OBD2 reader will be able to get your basic engine fault codes at least. The regular gas should not cause a check engine light. The routine maintenance light will come up in the center display and will tell you when service is due.

 

Thanks for the responses.
The car works so perfectly, I hate to take it to the dealer. NYS Inspection is not due for 11 months, so maybe this might go away on its own? (ha!) I don't know if a car can pass NYS emission inspection with the cel on. It has plenty of power and runs great, but I do not want to do any damage.

We have wiped available funds clean after Hurricane Sandy. I fill up 5 gal. cans every day to run a generator to heat my home. I don't need to give 1K to Porsche of Huntington right now. My regular shop, RPM North, went out of business. I will have to find a shop that could try to clear the code, and see if the cel stays off.

 

If it was the gas cap then it will go away in a few days.

 

Can u bring the p!g to me this Friday? ill be at TKX Performance. Ill check your codes. usually there 9:30-4.

 

Thanks Scottitude, I will be there on Friday afternoon

 

Believe it or not, it could be a problem with the booster vacuum lines/adapter (it equal no brakes at any moment). Mine is a 2008.

When the light came up 3 days ago I thought it was a problem with the emissions due to fuel. When the codes were read it was the booster vacuum lines/adapter. There are right now 7 (including mine) in Porsche certified shop were I took my Cayenne; from 2004’s to mine, a 2008 .

We are looking to see if there is a recall bulleting concerning this issue, since there is already the plastic cooling pipes precedent and a class action suit concerning that issue.

BTW It’s costing me $869.99 with parts/labor.

 

Well......technically ......according to the owners manual you can buy fuel in North America that would throw a check engine light. While simply running "regular" won't do it, the quality/type of fuel additives looks like it can.

Here is the page from the owners manual.

 

Got codes scanned: (thanks Scotitude)

P0456- Very Small Evap Leak- Have new oem gas cap coming today, will report back

P0657- Hvac Servos? Creaky, but works ok!

15504- Passenger Seat Airbag weight sensor? Pass air bag off light comes on at 5lbs, but works ok!

Durametric said engine, tranny, pcm, all areas all good.

Thanks Cole for the info. Hopefully the new OEM Cap will make the light go off in a few days/ 50 starts/ 200 miles/ or new gas fillup, from what I've learned.

 

CEL Off! Looks like the new oem gas cap fixed it, as code P0456 could now be cleared. 100 mi. so far.
My old cap had only hairline gasket cracks, barely visible. A wet gasket appears to be normal on both.
My CEL would not go off by itself with the new cap after 2 weeks and 200 mi. It had to be reset.

Many thanks to 'Scotitude' and TKS Performance in Huntington Station for all the help- now my new shop. That light was driving me nuts! I don't know how people drive with error lights lit- I sure can't. Takes away from the whole 'Master of your Domain' experience.

 

There are a certain number of error free start/drive cycles that must be completed before the check engine light will go off by itself. Don't know what that number is but I'm sure it's in the OBDII section of the service manual.

Many folks have issues with the 993's since they were Porsche's first models with OBDII but I've never had a problem with either 993, I can get the "readiness indicators" to set quite easily with a couple of drives. My '97 M3 is another issue though, sometimes it can be a pain. Seems to set much easier in cooler weather though.

Glad you got it resolved. Is there a part number for just the cap gasket?

 

I don't think you can get just the gasket, but the full oem cap assembly was only $24.00 @ Parts geek, and came in an official porsche bag.