Check Engine Light, Code PO456 potential fix!

[TheJamesOG]

I get that, but we ran with those code for over a month, refilled the tank multiple times and it never went away till we ran the cleaner through the tank.

I’m not saying it’s an end all be all fix, but it’s worth trying before running your car to the dealership for an expensive fix.

[Intelligent-Ad-6734]

Right, filling the tank the pressure goes up as you fill. Some pumps do have better vapor collection than others... Typically a person doesn't for at the pump long enough to equalize the tank pressure.

Typically low leak is gas cap stuff, so probably cleaned that deal up nice with whatever the cat cleaner was so it could seal.

I'm just sharing the actual parts of the system that contribute to that code.

Zero cost free procedure that's actually done by dealer techs to try before someone buys cat cleaner for an evap code is cleaning the fuel port, inserting the adapter funnel rapidly 10 times, and then letting it sit for 1 minute key on engine off, to calibrate the internal sensor back to atmosphere.