My check engine bulb DOES NOT illuminate when my key is turned forward in the start position? Everything else does though. If the bulb is burnt out or removed will it affect my driveability or trouble code storage??? I have an appointment on Mon morn to get it replaced & proper diagnostics done to find out why my car runs like dog-doo. I have had it at the dealer twice & spent over 600 bucks & I have told them my check engine light never comes on. You would think they would have checked that so far??