EVAP P0456 - Small Leak Detected - Smoke Test

Did a smoke test with the Canister Pump Vent Valve closed and opened via scan tool. Fuel cap is about a year old. Smokes comes out of the atmospheric vent on the LDP (Leak Detection Pump)whether closed or open. You can barely see it. Smoke also comes out around the gas cap whether the vent is closed or open. However when I close the vent it definately minimizes the amount of smoke coming out around the gas cap.

replace Charcoal canister and leak detection pump? I will link the videos later.

 

A little bit of smoke is normal on the atmospheric vent. I'd start with an OEM fuel cap and recheck. Also check all the lines and hoses, the truck is older and most likely has OEM hoses.

 

You got some nice tools there. I had to make a home made smoke detector to figure out the problem on my van.

 

I bought that Xtool D8 scan tool used on EBay. I did the math and to add each of our vehicles to some of the other less expensive bidirectional scanners it would have been about the same price.

I have a new OEM cap on it now. You think it would go bad in a year? I’m at work i will link the video later. Its a 2007 and im quite certain the hoses are original OEM

 

You have to unhook the vent hose from the fresh air port on the canister and cap the port to do leak test, closing the vent valve does not seal the system on Toyota leak detection pump systems.

 

thanks. I will rerun the smoke test.

 

Replaced the gas cap(even though it was only a year old) and the ventilation hose that goes to throttle body. Reset the codes and it has come back. The ventilation hose did have a very small crack on the end. I think it was the gas cap though. It’s been more than a week now.

 

fwiw locking gas caps have a reputation on here for being mixed luck on sealing properly. Guess I got lucky as the locking cap I got has worked without issue.

probably a good idea if you’re replacing it to have a lock system whether the cap or installing a lockable door.

 

Toyota does not play well with aftermarket gas caps of any kind especially locking ones, OE only on gas caps. Not sure why but you have maybe a 50/50 shot of an aftermarket one sealing properly.

 

i used OEM in both cases.