Jeep Wrangler P0456: Understanding and Resolving This Common Issue

If you’re dealing with an EVAP leak, replacing the gas cap is usually the first step. In this case, a 2010 Jeep Wrangler with a persistent EVAP leak had already gone through the process of replacing the gas cap to no avail. The vehicle had been taken to another shop that ran multiple tests, including a smoke test, but couldn’t pinpoint the issue.

The customer was unable to get the vehicle smogged in California until the problem was resolved. The first step was to rule out the gas cap as the culprit, which was already done. The next was to use a scan tool, the Anova 5610, to identify the trouble codes and to gather the Freeze Frame data. The codes that showed up were P0456 and P0455, indicating small and large EVAP system leaks respectively.

Several possible causes of the EVAP leak were considered, including the charcoal canister and the top of the tank. A handmade smoke machine using a pickle jar, a soldering iron, and some hoses was utilized to detect potential leaks. A cracked white plastic piece was identified as one of the issues, and a repair involving a roll pin and epoxy was conducted to fix the problem.

After completing the repair, the article described using the scan tool to erase the codes and initiate the drive cycle procedure to confirm the repair. Following a test drive and a battery disconnect, the EVAP monitor turned green, indicating a successful fix.

The article concluded with a final scan, ensuring that only one monitor remained incomplete, and a reminder to the customer to drive the vehicle a bit longer to address the remaining monitor.

What were the codes showing up on the scan tool?

The codes showing up on the scan tool were P0456 (EVAP system small leak) and P0455 (EVAP system large leak).

What steps were taken to identify the EVAP leak?

The technician used a homemade smoke machine to pressurize the system and identified leaks at the charcoal canister, gas tank, and EVAP lines using visual and smoke tests.

How was the cracked EVAP system component repaired?

The cracked EVAP system component was repaired by using a roll pin for added strength and epoxy to secure it in place. The repair was confirmed using a smoke test.

How did they clear the EVAP code and complete the drive cycle?

The technician disconnected the battery to clear the code and later completed the drive cycle, ultimately confirming the repair and passing the EVAP monitor.

What were the final results of the repair?

After completing the repair, the EVAP monitor passed, clearing all codes except for one incomplete monitor for the oxygen sensor, which is expected to resolve with further driving.

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