Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Inspection Procedure
HINT:
Read freeze frame data using a Techstream. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
- CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0121)
- Connect a Techstream to the DLC3.
- Turn the ignition switch to ON.
- Turn the tester ON.
- Select the following menu items: Powertrain / Engine and ECT / Trouble Codes.
- Read DTCs.
Result
RESULT REFERENCEResult Proceed to P0121 A P0121 and other DTCs B HINT:
If any DTCs other than P0121 are output, troubleshoot those DTCs first.
B: Go to DTC CHART (See DIAGNOSTIC TROUBLE CODE CHART )
A : REPLACE THROTTLE BODY (See DIAGNOSTIC TROUBLE CODE CHART )
NO RELATED
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.