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2005 Jeep Grand Cherokee 5.7 Hemi with P0132 and P0300: Random Misfire and O2 Sensor Issues

Model: 05 Jeep Grand Cherokee Fault Code: P0132 Posted: 2014-03-28 04:22

I own a 2005 Jeep Grand Cherokee equipped with the 5.7L HEMI engine. The issue I'm experiencing is that when I start the vehicle, it warms up normally and idles smoothly. However, as soon as I shift into gear, the engine begins to stumble and hesitate. During acceleration, a random misfire occurs, which persists until the vehicle reaches 60-70 mph. Once I slow down, the problem returns immediately. I've already replaced the spark plugs (less than a month ago) and the O2 sensor for Bank 1, Sensor 1, both of which were OEM parts. After the replacement, the symptoms temporarily improved but returned after three weeks. I initially suspected poor fuel quality, so I added a fuel treatment and ran through several tanks—however, the issue has not resolved. Using an OBD2 scanner, I consistently receive two diagnostic trouble codes: P0300 (Random Misfire) and P0132 (Oxygen Sensor Bank 1, Sensor 1 - High Voltage). The check engine light comes back on after any misfire occurs. I'm seeking advice on how to properly diagnose and fix this issue.

Related fault codes
P0132P0300
Comments (6)
Anonymous 2014-03-28 07:59

Has the check engine light returned? Are the same OBD2 codes still present? Did you replace the O2 sensor with one from an authorized dealer or OEM source?

Anonymous 2014-03-28 08:50

Please confirm the exact OBD2 code numbers—misinterpretations are common. Also, is this vehicle stock (no modifications)? Were both the spark plugs and O2 sensor original equipment manufacturer (OEM) parts? As a suggestion: perform a fuel pressure test and a fuel leak-down test using a proper gauge to rule out fuel system issues.

Anonymous 2014-03-28 09:37

Thanks for clarifying—I'm getting P0300 and P0132. The vehicle is stock with no modifications, and both the spark plugs and O2 sensor were OEM replacements. The check engine light initially turned off but returned after the first misfire occurred.

Anonymous 2014-03-28 11:31

I recommend following up on the fuel system diagnostics as suggested—especially the fuel pressure and leak-down test—to ensure the issue isn't related to fuel delivery or quality.

Anonymous 2016-03-05 13:30

I have a 2005 Jeep Grand Cherokee with a 4.7L engine. I recently replaced both catalytic converters and the O2 sensor, which triggered code P0132 (High Voltage on Bank 1, Sensor 1). After replacement, the check engine light came back on immediately with the same code. What should I do next to resolve this? Is it a wiring issue or a faulty sensor?

Anonymous 2016-03-05 15:59

The P0132 code does not indicate that a part needs replacement—it points to a circuit issue. First, inspect the wiring and connectors at the O2 sensor for damage or corrosion. Avoid using generic aftermarket wires—use OEM-grade wiring instead. For P0132 (Oxygen Sensor Circuit High Voltage - Bank 1, Sensor 1), do you have access to an OBD2 scanner that can monitor actual oxygen sensor voltage readings in real time? This will help determine if the issue is electrical or sensor-related.