Check Engine Light went on after car sat for a week! - P0154 code

I got back from a family vacation yesterday, and used the 996 to go pick up some food about 2 miles away. When I got back, the CEL came on. Do I have to take it to a dealer or mechanic, to find out what's what? Should I stop driving the car? I have a pretty comprehensive warantee from GE, with a $200 deductible. With the low miles and my car sitting around for a lot of it's life, what can I be in for? PS--Search engine is down...of all times!

First things first. Don't Panic If the CEL isn't flashing you are probably OK driving the car a little. Just go to a Porsche dealer or indy mechanic with a code reader and have the computer codes read. They'll be able to tell you exactly what the problem is. GL

there are lots of little "checks" the car does that can trigger a CEL- I just had one go on after I washed the car and then after about ten key cycles it went out. IMO I would wait a week or so as it may just correct itself.

Go to Autozone and ask them to read the code for you (free) then report the code to us.

Try this...disconnect the battery...then re-connect (this will clear the CEL). If it comes back...It might just be a week battery. Do you have it on a battery maintainer? If not you should...leaving the car for a week and such.

go to autozone get them to read the code and they can erase it. Someone here will read the code for you and tell you whats wrong. then you can decide to go to the dealer. You should have a code reader. about $100.00 and join renntech.org and they have a complete list of codes. most are minor, loose gas cap, O2 sensor etc. Going to a dealer or independent WILL cost you money and one trip to a dealer will pay for your very own code reader!!

Yep - your own code reader is a great investment! I went with: http://www.harborfreightusa.com/usa/...bCategoryName= Pays for itself in one use - and you get to know more about your car.

Good advice on getting a code reader. And good advice on disconnecting the battery to see if that clears the code light. The car does sit a lot, and I don't have it on a battery charger. My 944 never needed one, so I tend to think it's not the battery. But as long as the light isn't blinking, I wont do harm to the car by driving it, hoping the light goes out? How do you read codes on these cars? Is there a plug by the fuses, or what? Also, how much is that Harbor Freight code reader - I don't see a price!?

Andy - there is an OBD plug by the fuse panel under the dash on the steering wheel side (US). I usually power the car up with the key - but don't start the engine - then read the codes from the OBD II Scanner. Reader is currently $65 on offer from $130 original price Here's a web link with pricing: http://www.harborfreight.com/cpi/cta...emnumber=94217 CEL may go out by itself - but it's better to read the codes when you first get the CEL, and then use the reader to reset the CEL for you. That way you can see if you have more than one thing that is triggering CEL over time.

These cars have so many electronics...running all the time...that a battery maintainer is required if you leave the car a lot.

OK, which one is a favorite? How much do they cost, and how do they work - stick them into the cig lighter socket?

Many use the Porsche version that goes in the CL....I got the interstate one that connects hard to the battery terminals and has a plug that plugs into the outlet charger. Works great...will not over charge the battery.

No way I want to remove that thing every time I want to take the car out for a joy ride, especially in the colder months! There must be a CL version made by another company other than Porsche?

I use a trickle charging battery charger during the winter. I just connect it up once a week and let it do it's stuff. Visit Pep Boys and you'll see plenty of options. One point here though - a dead battery should not cause a CEL - I think that's a red herring. Need to get the code read and see what's going on.

Definitely buying a code reader. Worth the $60 investment to know what's going on, and to be able to reset the light at will.

CEL is generally related to emissons stuff-O2 sensor, MAF, vacuum hoses (could be cracked), loose gas cap. I had an Audi that I drove for thousands of miles with the CEL on and never gave it a thought. I would not do the same w/ P-car tho. Autozone has OBD II reader you can use and it can reset CEL or you can disconnect battery. Remember that if you disconnect the battery you will need the radio code to make the radio work when you reconnect. O2 and MAF and even cracked hose are wear items that even the mighty p-car is not immune from.

I just sucked it up and bought the old model of the Porsche charger - works like a charm to keep the battery charged up. Here's a few on EBAY: http://cgi.ebay.com/ebaymotors/Porsc...spagenameZWDVW As for low battery and CEL - not seen that one myself - but the trickle charger is worth the $$$ either way.

You do not understand how it works...my poor explanation...there is a hard wire connection to the pos/neg terminals...that wire comes off of this and sits in the trunk. It has a simple plug that connects to the device that plugs into the wall outlet. You can plug it in and close the hood and it trickle charges...no plugging into the CL through the door. Very easy install. Is it the original battery? If so it is due for a new one...and don't get a Porsche one. Yes a dead battery can throw a CEL. As far as code readers if you really want a good one that can clear even airbag codes get the durametric software. Battery Thread

I got a code P0154 - Code reader says "02 sensor (Bank 2 / sensor 1) So I erased the code, and took the car on a spirited drive. No light. Took the car back home, no light. Does this mean the CEL could have thrown a code to complain about not being driven for a week?

code= O2 Sensor Circuit No Activity Detected...if it does not return no worries...if it does...O2 sensor could be loose or disconnected.

Thanks for the translation! The car would run pretty poorly if the 02 sensor wasn't working, right? Could it be inactivity as the cause? Either way, the code reader just paid for itself!!

My manual says: Oxygen sensors (heating connection), replace oxygen sensor.

After the code is reset it will usually take a few drive cycles for the CEL to be triggered - so don't declare victory yet.

Revisit: 2 years later, I got the same CEL code, after keeping the car on an incline in front of my driveway. I believe it happened two years ago after I did the same thing. Could keeping the car on an incline after a drive cause CEL codes relating to O2 sensors and such?

I get O2 codes every three months or so just erase them.