metalhed

Greetings My truck has thrown a code, P0450 Evaporative Emission System Pressure Sensor/Switch, 4 times now. Every time it comes up the weather is cold.

I go to Checkers and pull and clear the code. Last time I bought a new gas cap and cleared the code. Yesterday, it was cold and snowy, I get in and start the truck to leave work, and the CEL comes on. This morning it is still on, this afternoon it goes out. It did get warmer today.

What is up with this code.

It seems everytime it pops the code it is cold outside.

My belief is the cold shrinks something (gas cap?) and allows air in the tank.

Am I on the right track with this code. Isn't this the code for the gas cap not being on all the way. I know there are other reason for this code, but the cap is the most common right? I want to start with with the simple stuff before digging deeper

thanks

darksoldier313

assuming u dont have a smoke machine a cheap alternative to figuring out where the leak is is very soapy water assuming it pressurizes at all ne more that is all though soapy water is kind of a hit and miss thing sometimes it works sometimes it doesnt spray around the cap first

rimpainter.com

Do you "top off" your gas tank by any chance? Normally that creates a 440 code, but who knows, maybe this is related. There is a way to "fix" it but it involves running down to E, then only filling to 1/2 tank a few times, then never topping off again.

When the fuel pump clicks I never go beyond another .15 - .25 cents.

BigBallsMcFalls

does your gas tank go whoosh when you pop the cap at half a tank after
shaking it up some (driving around) ?

other than that, yeah..there are a lot of hoses to check...