I have a 2000L w/ a C&L mass,filter & chip. I'm in MN and truck ran good all summer , but in last 2 weeks have had det. at WOT. Changed gas ,still had probelm. I added NOS racing oct. boost and seemed to fix. Does MN run a winter gas formula? Or is cold weather causing? Do I need chip reburn?(superchip). Thanks for any help.

 

As the weather gets cooler, I expect a lot more people
will start having detonation. Octane booster can help,
but a cold weather tune would be the best.

 

Hi mxluke,

This is one of many reasons why we advise eveyone with supercharged 5.4's to run the 2-program Superchip Flip Chip, so you can have both a warm weather and a cooler weather program, as the PCM adds & subtracts timing based on IAT (inlet air temperature), among other things.

When you get into cooler weather, you have more timing, and thus if you have marginal fuel quality or an aggressive warm weather tune, colder weather can put you right into detonation. And to make matters worse, at 104 mph the PCM adds in more timing, so if you drive it at higher speeds you can easily have inaudible detonation present even if there is no detonation anywhere else, and of course that will also make any detonation present below 104 mph just that much worse.

I suggest that for now, do not drive that vehicle in any manner during which you hear any detonation, and no matter what, do NOT drive it over 100 mph until the tuning is taken care of.

You can give us a call at our number listed below and have us take care of this for you if you like.

Good luck!