LGAFF

Getting the P0300 random misfire code on my 05 TT V12, no specific cylinder and the car goes back to running fine after the code set. Coil packs were rebuild last year, this issue started this winter when I went to put the car away. Any thoughts, my code reader does pick up on specific cylinder codes


Thanks

Lgaff

LGAFF

Ran it hard, not down on power at all...no codes when I ran it hard....came on at idle...strange

OldKneeDragger

There are a lot of possible causes of the PO300 misfire on the V12. I would start with the simple and most common problems. What gas do you run? From a Top Tier station? If not, run, don't walk to your local auto parts store and get some Chevron Techron and run a tank full. It's always worked for me and solved my misfire issue. I run a bottle about every other tank as I don't have a top tier station near me.

(FWIW, the guy I bought the car from changed the ignition rail and the plugs trying to solve this issue before giving up and selling it to me. A $8 bottle of Techron solved the problem and I've never had it again with over 30K miles added to the odo....)

If it's not a fuel issue it could be anything from the fuel injector to a plug to the ignition rail and everything else in the circuit. None of which are as easy to find & fix.

Keep track of which cylinder caused the misfire, it may help figure it out if/when it happens again.

LGAFF

I think its my tune combined with the winter blend gas, I believe they start summer blend this month.....will try the additive in the short term. I generally run Shell or BP.....odd thing is I stopped using a SHELL station near my work as it was causing my C32 to shut down on full throttle.....this is not the same station I use for the SL....

Thanks for your input

LGAFF

Still getting this code....comes on at part throttle have not seen it at idle....car still runs great idles at 600-630 pulls strong no obvious vac leaks

Tried the gas additive, new gas in the take so should be beyond the winter gas issue


thoughts?

LGAFF

Went 90 miles today, then out of the blue at light throttle got the CE light


I am not feeling a miss with the car