P0455 Code: EVAP Large Leak — Can’t Find The Leak Even After Replacing Gas Cap!
Quote from LadyGreaseHands on June 16, 2025, 10:50 amHey guys,
My 2012 Honda Accord keeps throwing the P0455 code for a large EVAP leak. I’ve already replaced the gas cap with a brand new OEM one but the code still comes back after a few drives.
I visually checked all the vacuum lines and hoses that I can access, but I don’t see any visible cracks or disconnections. I don’t have a smoke machine, so can’t check for micro leaks.
Could the purge valve or vent solenoid be the culprit? Has anyone fixed this without needing a smoke test?
Any advice would be greatly appreciated!
Hey guys,
My 2012 Honda Accord keeps throwing the P0455 code for a large EVAP leak. I’ve already replaced the gas cap with a brand new OEM one but the code still comes back after a few drives.
I visually checked all the vacuum lines and hoses that I can access, but I don’t see any visible cracks or disconnections. I don’t have a smoke machine, so can’t check for micro leaks.
Could the purge valve or vent solenoid be the culprit? Has anyone fixed this without needing a smoke test?
Any advice would be greatly appreciated!
Quote from CarGuyBrad on June 16, 2025, 11:10 amStart with the gas cap — make sure it’s tight and sealing properly. If that’s okay, check the EVAP hoses for cracks. Smoke testing can help locate hidden leaks quickly.
Start with the gas cap — make sure it’s tight and sealing properly. If that’s okay, check the EVAP hoses for cracks. Smoke testing can help locate hidden leaks quickly.
Quote from CodeHunterJoe on June 16, 2025, 4:29 pmThis is a tricky one — if the gas cap didn’t solve it, I’d check for cracked EVAP hoses, especially near the charcoal canister or purge valve. A smoke test is usually the fastest way to locate small leaks you can’t see easily.
This is a tricky one — if the gas cap didn’t solve it, I’d check for cracked EVAP hoses, especially near the charcoal canister or purge valve. A smoke test is usually the fastest way to locate small leaks you can’t see easily.
Quote from CheckEngineChamp on June 17, 2025, 2:56 pmA P0455 code means the EVAP system has a large leak—so even after replacing the gas cap, the code can return if the actual issue lies elsewhere. The next best step is to smoke-test the system to pinpoint hidden leaks in hoses, the filler neck, charcoal canister, or purge/vent valves
A P0455 code means the EVAP system has a large leak—so even after replacing the gas cap, the code can return if the actual issue lies elsewhere. The next best step is to smoke-test the system to pinpoint hidden leaks in hoses, the filler neck, charcoal canister, or purge/vent valves
Quote from ScanToolGuru on June 18, 2025, 10:44 amIf replacing the gas cap didn’t fix the P0455 code, the leak could be from a cracked hose or faulty EVAP canister. It’s best to do a smoke test to find small leaks that are hard to spot. A mechanic can easily handle this test.
If replacing the gas cap didn’t fix the P0455 code, the leak could be from a cracked hose or faulty EVAP canister. It’s best to do a smoke test to find small leaks that are hard to spot. A mechanic can easily handle this test.
Quote from AutoFixerMike on June 19, 2025, 11:12 amIf you’ve already replaced the gas cap and the P0455 code still shows, the next step is to check for leaks in the EVAP system hoses and the charcoal canister. Small cracks or loose connections can trigger this code. A smoke test is one of the best ways to find hidden leaks that are hard to spot by eye. You can also check the purge valve and vent valve — if either is stuck open, it can cause a large leak code.
If you’ve already replaced the gas cap and the P0455 code still shows, the next step is to check for leaks in the EVAP system hoses and the charcoal canister. Small cracks or loose connections can trigger this code. A smoke test is one of the best ways to find hidden leaks that are hard to spot by eye. You can also check the purge valve and vent valve — if either is stuck open, it can cause a large leak code.