I started regularly getting a CEL this season. It flashes for about 10-15 seconds and the turns off. These are the errors:


Misfire errors occur once in 3 days. I cannot re-create the conditions under which it happens. Sometimes it's during hard acceleration (or right after it), sometimes when I'm just cruising. It's pretty much random.

The P0001 error occured a couple of days ago. CEL stayed on for a day and then went off.

PIWIS diagnostics at my workshop showed NOTHING wrong with any of the parameters. Spark plugs were changed a year ago, coils were changed just recently. No effect.

I did not drive the car in winter, errors started occuring since spring.

Shop wants to swap oxygen sensors to see if the errors will transfer to cylinders 4-6. But it seems a bit of a hassle, cause I will have to drive the car for a couple of days for results.

Any suggestions?

Could it be bad gas quality? I moved in fall and changed my gas station obviously..

 

You need to change sparkplugs and ignition coils.
Which plugs did u put in? is your car tuned.

 

Well, that's what I wrote. I changed sparkplugs at the end of last summer. Drove a bit in fall, then problems started to occur after I had taken the car out in spring this year. I did change ignition coils, but that did not help.

Car is tuned by Wendland in Germany (K16 billets, intake, exhaust, flash). It should've been around 580hp in 2002, I doubt all horses are there now. Plan to dyno it after I'm done with repairs.

 

As you have replaced your coils and fitted the correct plugs, Id check for vacuum leaks buddy

I'd say the vacuum hose to your Fuel Pressure Regulator has either perished or broken either that or a vacuum leak else where.

 

Your FPR hose could have come disconnected. On my 997 turbo it did and it caused a lot of issues that were hard to track down.

 

I have the same misfires on one bank only. New plugs and coils didn't help at all just like you. I've done a pressure test and replaced O2 sensors. A buddy of mine works on a lot of Porsches at his shop and he's 99% sure it's the Cam actuator on that bank. The bracket that holds it in is in good condition (sometimes a problem on these cars). I'll be replacing the actuator as soon as it arrives, and report my findings.

 

Vogz... yes it's the variable valve lift I be leave . Had the same problem. That solinoid is on the top back not on the cylinder head with the bracket. Try taking the electrical connection off and back on a few times. That fixed mine.

 

Are you talking about this:


or this:


Mechanic buddy of mine said it was the first one with the bracket.

 

I think it is the second one. They are located were I circled.

 

Interesting. My Porsche mechanic buddy said he's never had to change those, only the ones with the bracket.

 

Right I didn't have to change them eather. The electrical connector was not making good contact. I just took it on and off a few times and used contact cleaner and the problem went away.

 

Ah, ok, I'll try that too. Thanks!

Edit: Did you access the plug from the top or bottom of car?

 

Never mind, I pulled Airbox and it was right there. Cleaned connection and re-installed. Test drive today.

 

I had a similar issue and changing to the correct plugs recommended by the tuner fixed the issue. I have K16 billets, injectors, and 1.2 bar tune.

 

+1 correct