Mods:
LT4 hotcam
MAC headers
PCMforless tuning
other misc boltons

I am having an issue where when the outside temp is cold say 50 or below my car runs a bit more rough. I will get 1-5 degrees of KR at medium throttle. The idle will jump around and it will run rich to the tune of losing about 50 miles to a tank.

Now if the outside temp is 60 or above the car runs absolutely flawless.

I think it is temp related b/c when it warmed up all my car problems disappeared. We had a cold front push through this week and it is down in the 30s and my car is acting up again. Any ideas?

I have replaced every sensor except for the waterpump coolant sensor.

 

Sounds like it might be a tunning issue, or you need to put in a lt4 Knock sensor to support your mods. Wish I could be more help, best I can come up with the information provided.