ok im trying to run my turbocharge accord with the stock ECU, and i got a FMU 12:1(vortech), an external MSD pump, and an inside the tank walhbro pump. i got a missing link for the MAP sensor, and still the check engine light still on. WHY???. it was on before i installed the missing link, and i changed the oxygen sensor also. so i disconnected the battery cable and turn it off. However, when i turn the car on the check engine light comes back. WHY???

 

what year is your car ?
get a code reader or do the jumper trick and pull the code out, that will tell you whats wrong

check engine means = something not working or missing (so check engine)

 

hard code? soft code?

is all the vaccum lines routed correctly?

missing link installed backward?

and most important thing, what code are you throwing?