Engine code P455

[JC316]

Good lord IDK what cycle im on. But no where near 50 i bet. Still on. I assume Ill be replacing the fuel pressure switch i guess.

Side note, will a EVAP leak/gross leak cause gas mileage to take a crap?

Dude, just go out and and disconnect the battery for a few minutes.... Yes, my Blazer had an EVAP leak and the sucker went from 19mpg down to 11mpg.

[Tannerm]

Ok so far the VMV was not the fix. I cleared the codes by disconnecting the battery. About a fill up later it came back on. So to recap. VMV has been replaced. As have the gas cap. All within 2 months. Curious what the hell else could need replacing to remove the p0455 engine code. Fak!

[HOOCBB]

I had to replace the filler tube on my old Ranger for a gas smell...it never tripped the CEL, though.

On the same truck, I had to replace the EVAP purge valve and purge flow sensor and the vacuum lines associated with them for a different EVAP related code.

If you smoked the fuel system and the only place it smoked out was the tank vent, then that is where you need to focus your efforts. When you say "tank vent", are you talking about the vent tube that runs along side the filler tube? If it is leaking close to the gas tank, it is very possible that it may be leaking fuel, which would make it appear to get bad MPG.

At this point, without seeing it, I'd venture to say either vent tube (from the tank to the filler neck), or the tank itself is cracked.