Justhereforinfo

iTrader: (2)

Just dropped a 5.7 long block into my 03 silverado. Everything besides the long block is from the original 4.8 that came in the truck. I towed it to my tuner (who has a very good reputation and is highly recommended). One day later it threw a CEL. I had it scanned at an auto parts store and found codes p0101 and p0300.

Can the p0101 (maf signal out of range) code cause the random misfire code?

Are these codes something that need attention? Or can they be a byproduct of a tune? Meaning, are they codes that commonly pop up due to having a modified tune, and are no concern for alarm?

I have a rough idle, and occasionally my converter doesn't lock up when cruising.
My research shows that many things (such as misfire codes) might cause the computer to not demand lockup.

Justhereforinfo

iTrader: (2)

I mentioned these codes to my tuner. Seems the custom cam was being detected as a misfire by the crank position sensor. He also tweeked the maf settings. Truck is running perfect. Im really enjoying my homemade ls6 now