my mom's civic's CEL came on today... i went ahead and checked the code, and i got code 90.

90 : Evaporative Emission Control System : Fuel cap loose, poor vacuum connection, fuel tank, fuel tank pressure sensor, EVAP bypass solenoid valve,
EVAP tow-way valve, EVAP control canister vent shut valve, EVAP canister, EVAP purge control solenoid valve


i checked the obvious, and yes the fuel cap was lose.. i tightened it, but the CEL is still on. if that was the problem, would the light just turn off? do i need to do some driving? how do i get the light to turn off???

 

to clear the code you need to reset the ecu.

 

take the negative wire off the battery for a couple of minutes, then put it back on