My 2015 Dodge Ram 1500 Express model, 86,000 miles, signaled that the gas cap was off on the dash. Before I got the new cap installed, the check engine light came on. Replaced the cap, cleared the codes by unhooking battery, drove fine for 10 miles or so before the check engine light came back on. This time no gas cap signal on the dash.
Had the code run at Oreillys and it’s P0440. I checked the purge canister under the hood and it seems fine. I pulled it out and could not blow air through it so reinstalled it. Is that a good enough test for the purge canister?
I do not smell gas vapors and the truck is running fine, what else do I need to check? I can take it for a smoke test but wanted to check what I can first.
Visually inspect the vent canister and vent system plumbing.
If there’s nothing obvious (like a disconnected or broken hose), then smoke test the fuel tank and vent system.
I don’t see anything odd so bought the sensor under the hood and the one on top of the gas tank. I replaced both earlier so it’s got two new sensors and a new gas cap. Light is still on but I read it can stay on a few days.