P0455 Investigation on Your 2021 Jeep Gladiator
P0455 on your 2021 Gladiator means the PCM detected a large EVAP leak. Your 3.6L Pentastar V6 and truck bed aren't affected—this is a vapor system issue. Like the Wrangler it's based on, the Gladiator is prone to gas cap issues from off-road exposure.
Symptoms
- Check engine light with P0455
- Possible fuel odor near rear/bed area
- Gas cap loose or contaminated
- Emissions test failure
Causes by Likelihood
- Gas Cap Seal (Very High Likelihood): Trail dust and wear. $10–$25.
- EVAP Canister Vent Valve (Medium Likelihood): FCA vent valve. $150–$300 installed.
- Purge Solenoid (Medium Likelihood): Sticking valve. $140–$280 installed.
- Vapor Line (Low-Medium Likelihood): Underbody exposure. $100–$250.
- Charcoal Canister (Low Likelihood): Water intrusion possible. $200–$400 installed.
Off-Road Consideration
The Gladiator shares the Wrangler JL platform. Off-road use, dust, and water fording can contaminate gas cap seals and EVAP components. Clean the filler area after trail use.
Warranty
Basic warranty (3yr/36k) has likely expired. Federal emissions warranty (8yr/80k) covers EVAP through 2029.
Safe to Drive?
Yes. P0455 doesn't affect the 3.6L V6, 4WD, towing, or truck bed functionality.