Did a evap smoke test. Closed the vent valve. Smoke seemed to be pouring out of the fuel cap. Figured that was my problem for my p0442 code. Pretty new ac delco cap like a few months old. Figured that was my issue when I went to purchase a new one I seen it said vented. Are the gas caps vented? Or is there a brand you guys would recommend?

 

I went down the evap rabbit hole, ended up being filler tube to tank was rusted. Also replaced vacuum line that runs over left rear tire on top of frame to engine. I recommend genuine gm cap. It solved my problem.

 

I seen a very small amount of smoke from the rubber hoses connecting filler neck to tank so pulled it and replaced those and the gas cap was my main leak. Went to turn the key and had fuel spraying from the supply line and return all of it is super rusted right there so now replacing fuel lines. Probably bumped them when taking the filler neck out.

 

What are you using for smoke testing?

George

 

Autoline pro Smoke machine I got off Amazon. Worked better than I expected for the price.

 

They sell a poly line kit for fuel line replacement, cheap easy and fast. Used it when I replaced the tank. It sprung a fuel leak when I replaced break line to back axel.

 

waiting on the nylon kit to come in the mail right now should be here soon! Then I get to test drive make sure the p0442 goes away. Thanks fellas appreciate the help!