After having a bad experience in a local shop, which ended up with several problems with no accountability, unrelated to the suspension height adjustment I requested, my car is now sporting a few CEL codes. I've taken the car to the dealership to repair them.

P0300 (misfire detection) - replacing spark plugs with Bosch FR6s gapped at 0.03.

P1109 (Input variables, charge measurement - above limit) - not sure about this. Used to get it a lot with GT28s PRIOR to upgrading to the Hitachi MAF. Any input would be appreciated.

P1508 - (408 Torque comparison function monitor - signal implausible). Never seen this 1 before. Porsche manual diagnosis suggests replacing the "faulty DME". Anyone familiar with this code?

https://www.6speedonline.com/forums/...any-guess.html

https://www.6speedonline.com/forums/...-s-onelap.html

Thanks in advance!

Mike

 

Hi Mike!

Sorry to hear of your code problems. These issues can be some of the most frustrating problems with these cars. The misfires will probably be taken care of with new plugs. EVOMS is recommending these now for our cars(Denso PK20PR-P8). I have used the Bosch FR6s too and they were good.
I have some experiance with P1109! Check this...
https://www.6speedonline.com/forums/...ml#post3007593
You might also look for other boost leaks, dirty throttle body, or MAF problems.

The other code I dont have any experiance with.

Hope that helps!
Mike

 

Something I forgot to mention, but that you are probably aware of, is cracked coils also give misfires. So if your coils are old you may consider changing them at the same time.

 

Thanks Mike. I'll check the FPR line. All coils were replaced a couple of years ago. I'm due for a boost leak test. I'll do that this weekend.

 

Ive seen the P1508 code on 2 996tt's. Both were fixed with new DME's.

Keep in mind its very easy to throw that code with incorrect tuning as well. If you have a custom tune, go back to an off the shelf file before purchasing a new ecu.

 

Tony, do you repair DMEs?

I am also getting a lot of misfire codes as well with new coilpacks and plugs only have 3K on them? What plugs are you recommending with my setup? Does meth lessen the lifespan of the plugs?

 

New plugs solved all codes.

 

Great news Mike!!

 

Ive gotten 1508 on a friends 996tt before. turned out to be a a sensor short causing noise (engine speed sensor). car wouldnt start while the code was thrown but after the DTC was cleared it was fine. maybe check the engine speed sensor or shorts. it could be alot of other sensors though. start with the sensors that are nearest the suspension. camshaft sensor maybe? im not a professional i just fiddle alot.

 

It could be a burnt brain. but is not that easy to burn out the ecu to the point where the engine wont run.. let alone just coz..... i dont think a faulty DME would be able to throw codes really..(faulty hence cant work.. my understanding of the DME works is kind of limited0 probably just something really integral to the ecu, sensor wise, is doing something strange.

dont believe everything I say but it wouldnt hurt to check.

Good Luck!

Edit: NVM i skipped reading the last 3 posts.

congrats!! it worked!