i just finished installing my turbo kit. I was driving around town and the check light came on. Also my A/F gauge was reading lean. any how i reset the ECU and rechecked my work oil leaks, vaccum, ect... then took it out again. The light came right back on after 5 mins. Can it be my check valve? The car still pulls hard even with the check light on and the A/F gauge reading lean.