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2000 Jeep Grand Cherokee Laredo 4.0L Fault Codes P0302, P1391, P0351, P0352, P0353 - Diagnosis and Repair Guidance

Model: 200 jeep Fault Code: P0302 Posted: 2015-06-16 08:40

My 2000 Jeep Grand Cherokee Laredo with a 4.0L engine is displaying multiple OBD-II fault codes: P0302, P1391, P0351, P0352, and P0353. Initially, the vehicle only showed P0302 (misfire on cylinder 2). We replaced the spark plug, plug boots, coil pack, camshaft position sensor, crankshaft position sensor, and inspected fuel injectors as part of troubleshooting. After these repairs, new codes began appearing. The vehicle now exhibits poor performance—lacking power, stalling intermittently, and failing to maintain speed beyond 60 mph. The original cylinder #2 spark plug was dry and black in color. We used all OEM components and the vehicle remains stock with no modifications. I am seeking expert advice on how to diagnose and resolve these persistent codes, especially given that P0351–P0353 relate to ignition system issues and P1391 points to a potential camshaft position sensor or wiring fault. A fuel pressure test is also recommended to rule out fuel delivery problems. Additionally, the 4.0L engine has known harness rubbing issues at the rear of the cylinder head—this area should be inspected for damage or wear.

Related fault codes

P0302P0351P0353P1391

Comments (5)

Anonymous 2015-06-16 08:54

Is the vehicle stock with no modifications? What specific components were replaced — note that this is a 'coil pack' system (COP), not individual spark plug wires. Did you use original equipment manufacturer (OEM) parts? How does the vehicle perform under load? If it runs smoothly, try resetting the codes and monitoring for reoccurrence. Was there any misfire or performance issue before replacing the coil, cam, or crank sensors? What was the condition of the old spark plug — wet, dry, black, or tan?

Anonymous 2015-06-16 10:34

Yes, the vehicle is stock and has no modifications. The 'wires' replaced were actually the plug boots connected to the coil pack, not individual spark plug wires. All parts used are OEM. Currently, the vehicle runs poorly — it would go through gears but start shaking at around 50 mph, stabilizing only above 60 mph before becoming unstable again when decelerating or accelerating below that speed. Now, the engine lacks power entirely and frequently shuts off unexpectedly. The original spark plug in cylinder #2 was dry and black.

Anonymous 2015-06-16 11:40

Since there were no prior ignition-related issues before replacing components — especially with only P0302 initially — it's critical to reinspect the coil pack installation. Check for proper seating of boot seals, springs, and harness connectors. Look for bent pins, corrosion, or loose connections in the plug harness. Perform a fuel pressure test: measure pressure when the engine is running, then monitor pressure drop with the key on but engine off (KOEO). A significant drop may indicate fuel delivery issues. The 4.0L engine has known wiring problems at the rear of the cylinder head — inspect this area for fraying or damage. However, since only P0302 appeared initially and no other codes existed before part replacement, verify that all repairs were properly executed. Ensure you have a reliable OBD-II scanner — do not rely on key cycling to retrieve fault codes.

Anonymous 2015-07-17 06:32

I'm experiencing issues with my 2000 Jeep Grand Cherokee. After replacing the crankshaft and camshaft position sensors, new codes appeared: P0351 and P0353. The vehicle runs poorly when cold — it only operates normally once warmed up, typically reaching speeds of about 50 mph in city traffic. I tried swapping spark plugs from cylinder 1 to cylinder 2; after the swap, code P0351 disappeared but P0353 remained. The engine now stalls frequently and lacks power. I cannot afford further repairs. Please advise urgently.

Anonymous 2015-07-17 11:20

Mazury — you should have started a new topic for your issue, as it differs from the original post. Is this vehicle equipped with a 4.0L engine? What are the current fault codes being displayed? Are all parts OEM and installed on a stock vehicle? Some early 2000 Jeep Grand Cherokees had known wiring harness issues at the rear of the cylinder head, which can cause injector or camshaft position sensor faults. If you're able to provide more details, we can assist further with diagnosis.