Flashing CEL is an indication of a problem that puts the converters at risk.

Without the error codes my WAG is most likely a rich misfire condition.

But you really need to pull the error codes. I travel with an OBD2 code reader in my Turbo. While it has an OBD2 data logger connected to the OBD2 port I prefer to be able to immediately retrieve the error codes, get the freeze frame error code and freeze frame data, check for any pending error codes, and view some engine telemetry in real time to try to determine what's going on.

 

I am waiting to hear from my shop tomorrow. But judging from the way the CEL pops up, I'd say the error codes will still be identical to those I had posted earlier.

 

https://www.6speedonline.com/forums/...ter-years.html


This is why I ask about the voltage

 

13.4v

 

That is definitely low. Should be 13.8 to 14.2. .

 

my bad, it's actually 14.08V (13.88V when warmed up) so the problem is not there

There was no snow today, so we swapped the O2 sensors and took the car for a drive to see if the misfires shift to cylinders 4, 5 and 6.

Alas, the problem remains. Misfires on 1-2-3 + P0040

To sum up of what has been done up to this day to solve the issue:
- new spark plugs
- new coils
- new n75 valve
- new variocam solenoid
- cat delete

Man, is this is ever going to end??

 

What coils did you use?

Heres the important one. What is the gap of the spark plugs? You need to have .024 - .026


Also what spark plugs did you use?

 

OEM Coils
Bosch FR-56 plugs (stock gap)

Plugs were changed a while ago, misfires started happening after 3+ months

 

Bosch are ok but there cheap spark plugs and i hated them i had misfires after a couple months too. I got the denso spark plugs from Todd my problems went away. They are 80.00 though.

Another issue is your gap there is your problem .026 atleast you need to be at but stock gap is .036 not good.


Order these:::::

denso pk20pr-p8 and gap them at .024

 

Well if there are no further suggestions, I might try changing the spark plugs. However, my shop says they've been using them on all cars and neither had a problem like mine.

 

I had the same problem everytime after 3k mikes. So many misfires on this forum from bosch plugs also they are iridium. Our cars dont like that.


Also your gap is stock thats not good.

 

I see. But do you think misfires on left bank ONLY (1 to 3) could be related to plugs? I would've thought they would be more specific if one or two plugs are faulty?

 

cross posting as 550hp is on the right track but I'm guessing also..but have had cel issues from old 02's.

so, by "swapping" 02's did you mean "replace" or just swap? id replace with new...and you could still have a cracked coil. i'd check those again also in spite of their relatively new installation.

clue might be found here:

What the P00040, P0041 code means

P0041 means that the engine control unit (ECU) is seeing the signals for oxygen sensor 2 has switched between the left and right banks. The bank 1 sensor 2 signal is swapped with bank 2 sensor 2 causing the ECU to trigger a Check Engine Light on the dash.

P0041 has a few common causes:

Swapped connectors between oxygen sensor 2 left and right bank
May indicate ECU failure or error
Wiring damaged, open, or shorted
Swapped oxygen sensor wiring between banks

also, if you're running a "5" range plug, that's what was oem until porsche decided to go hotter with a bosch fr6ldc. that's what you should use pre-gapped out of the box or ( my tuners all gap to .027. ) btw. not for nothin, my car LOVES the fr6ldc. been using em for years

also, i'd make 100% certain you have NEW 02's. not just "swap" them pre to post(?) if i am correctly understanding what all you did with them.

 

I swapped between left and right. If the problem was in the left O2 sensor, then it should've migrated into misfires for cylinders 4-5-6, right? But it didn't!

ECU failure, can that even happen?

 

its the brass bracket on the side that holds the solenoid.. $18