2001 Town & Country P0455 Code: Large EVAP System Leak - Diagnosis and Fixes
I own a 2001 Chrysler Town & Country with a persistent P0455 diagnostic code indicating a large evaporative emission system leak. I've already replaced the gas cap, which reset the code temporarily—only for it to return. I then replaced the purge valve under the hood and performed another reset, but the code reappeared. After thorough inspection of all hoses and connections, no visible leaks were found. I'm now wondering if there's a common issue specific to this model year or if I'm missing a key step in the diagnosis. Since I have an upcoming inspection, I need a reliable solution before then. Any insights into potential causes or testing methods for this vehicle would be greatly appreciated.
If no other diagnostic codes are present, the most effective method is to perform a 'smoke' test on the EVAP system. The smoke helps technicians visually identify the exact location of any leaks.