Code P0456, gas leak

Hi Eddy,

P0456 means there is a small leak detected in the evaporative emissions system. Most of the time I see this code its related to the fuel cap being loose or the vent in the cap failing. Other times I see it, when there is a cracked vent line, or fitting.

The test you are talking about is called a "Smoke test" where a smoke generator is used to safely make smoke that is pumped into the fuel system vent lines. These are specialized units that can be purchased online even. They make smoke using an electric coil and a fluid (like baby oil) to make a thick white smoke.

This is something you can do yourself if you want to make the investment in the machine to do so.

I use them all the time and they really do make leaks of even small sizes easy to spot.

Hope that helps.
Jon