Just curious if colder spark plugs (TR6's) could cause a random cylinder misfire code P0300? I put in the TR6's because I am going turbo soon, gapped at 0.035 I believe. Had TR55's gapped at 0.055 before without any issues. Same plug wires and coils. I cleared the code to see if it will come back but I've only driven it twice since.

 

not a fan of projected tip for boost as a side note, but it can happen. i tried to go from tr6 to tr7 with my old nitrous setup and it would set miss codes

 

i would recommend the br7ef. its non projected tip. good for boost. part number is 3346

 

there shear number of customers coming into my store for oxy sensors and requesting to have codes read for p0300 is bafleing this winter. nothing like this happened the last 2 winters. im wondering f something is up with the ethanol blend in the fuel in this region thats doing this to vehicles. Im talking everything from inline 4 bangers to LS2's having the same issue.

 

Ethanol doesn't burn well when cold. Vehicles not designed with E-fuel in mind may run poorly in cold weather.

In my truck, on a 40 degree day, cold start with E85, it stumbles and misses for the first 30 seconds. After that it smooths out...but it's designed and programmed for E85.

 

Check and see what C5606 is set to. Set it to 1500 if it's not already similar.