P0121

TROUBLESHOOTING HINTS
This diagnostic trouble code (DTC) can not be assigned to any single component because the trouble code represents a comparative discrepancy failure between two sensor inputs within the multiport fuel injection (MFI) system. Since the failure of multiple interelated components could cause this type of malfunction, it may be necessary to evaluate the MFI system with an overall view.

NOTE:
- Begin with the inspection and verification of both, Mass Air Flow Sensor and Throttle Position Sensor circuits for proper operation.
- It is highly possible that this DTC will be accompanied by additional DTCs that could prove helpful in narrowing the scope of potential MFI components to investigate.