70 LS1

iTrader: (1)

Does running open headers cause you to run rich or lean? Why?

thanks

WILWAXU

iTrader: (6)

Just a guess.. but I figure it would make you run richer.

John B

iTrader: (10)

On a carburetored motor you will run lean because the reduced backpressure enables the motor to flow more air and the A/F mixture leans out. On an EFI motor, this increased airflow will be sensed by the PCM via O2's and it will try to compensate by adding more fuel. Unfortunately the PCM really needs to be recalibrated so typically too much fuel is added by the PCM thus causing the motor to run too rich.