Jeep Liberty cylinder misfire issue with codes P0301 and P0300, suspected voltage leak requiring coil packs, wires, and spark plugs replacement on Jeep Liberty

Submitted by gomezp · Jun 23, 2025
Published by RepairPal

Problem overview

Some Jeep Liberty owners report experiencing cylinder misfire issues indicated by error codes P0301 and P0300, which may suggest a voltage leak and necessitate the replacement of coil packs, wires, and spark plugs. Diagnosing the cause of the misfire, particularly in cylinder one, is crucial for resolving these codes. Owners have found that swapping spark plugs and assessing their condition can aid in troubleshooting the P0301 code. Common repair steps include replacing spark plugs, fuel injectors, coil packs, and various sensors, as failing to do so can lead to more severe and costly repairs, such as a $5000 valve job recommendation from a dealer. Additionally, troubleshooting may involve checking for a leaking valve cover, inspecting the O2 sensor for oil contamination, testing spark plugs and coils, and performing compression tests to identify the root of the misfire.

2 people reported this problem
1 comment
Schedule Repair

Jeep Liberty vehicles with this problem

1 model year affected
Average mileage: 72,400 miles
(72,400 - 72,400)

Search for another problem

RepairPal Car Genius

Ask our experts about your Jeep.

RepairPal Car Genius™ is a free resource for vehicle owners seeking advice on maintenance, auto repair, shop inquiries, estimates, and finding a trustworthy repair shop in your area.

 Auto Repair Expert Auto Repair Expert

Call us at 877-913-1554

Available 9am – 6pm ET Monday through Friday

Call Our Experts