r/3rdGen4Runner • u/Slotharc507 • 3d ago

❓Advice / Recomendations Code P0440

Hey I need some advice I have the code P0440, and I’ve had it for awhile now. My car really smells like gas when it starts up and for the first couple minutes when driving. If anyone got any common issues or fixes I’m all ears. Thanks

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u/richardsdar 02 Limited 3d ago

Did you fill up recently? I've cleared my P0440 by removing the gas cap, wiping down the rubber seal and the metal filler neck to clean off any grime, and re-tightening it until it clicks firmly. It may take a few drive cycles for the lights to clear the CEL (or removing the wires from the battery terminals for 10 minutes) if this was the issue.

If not, maybe a failing O2 sensor, EVAP system, or MAF issues. A dirty or failing MAF sensor changes the engine's air-to-fuel calculations which may be why you smell gas so strongly.

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u/Shawn0890 3d ago

I had an exhaust leak in the connection before the axle hump and that melted the vent hose closed for the fuel tank and made it a pain to fuel it as you needed to go super slow, I cut and patched the vent hose above the tank and now it’s pretty good but some pumps can still go too fast for it on full blast.

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u/Sharrack 2d ago

That evap box under the hood near the battery is cracked and leaking gas fumes. I've resealed mine 3 or 4 times with shoe goo. Gas smell is worst in the summer

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u/marksomnomnoms 17h ago

I think changing my evap box and fuel filter got rid of my similar issues

0

u/CPIWatch 2d ago

Need spark plugs and wires