I recently performed an OBD2 diagnostic on my 2002 Jeep Grand Cherokee 4.7L V8 and received three trouble codes: P0206, P0121, and P0455. I'm looking for a clear explanation of what each code means and how they might affect the vehicle's performance. Any insights or troubleshooting steps would be greatly appreciated.
Thanks for the link. I have another concern: after installing a new fuel pump and replacing my spark plugs, I've started noticing a gasoline odor inside the cabin. The vehicle now sputters and occasionally shuts off—especially when idling at a red light. It will hesitate, then sputter as if about to stall. I’ve had to shut it down manually and restart it several times. Could any of these OBD codes be related to this issue? Any advice would be much appreciated.
A fuel odor combined with code P0455 is likely connected—this may indicate a leak in the evaporative emission system. Regarding spark plugs: what brand did you use? This detail matters, as non-OEM parts can affect engine performance and misfire detection. For hesitation and sputtering: - Code P0206 points to an issue with the fuel injector circuit—possibly wiring or injector malfunction. - Code P0121 suggests a problem in the throttle position sensor (TPS) circuit, possibly due to loose connections or signal interference. Additional note: Does everything else function normally? For example, cruise control, air conditioning, and horn?
Yes, all other systems—including cruise control, AC, and horn—are working properly. I used a non-Mopar brand spark plug from Auto Zone; I didn’t realize that might impact performance.
https://www.obd-codes.com/p0121 https://www.obd-codes.com/p0206 https://www.obd-codes.com/p0455