Engine Knock and EVAP code

I have a 2001 4runner 3.4L, 170k miles. I keep getting an Evap code, I’ve replaced the vent circuit, charcoal canister, lines and it the evap code is still popping up.

Now I have an engine knock when idling.

I just did an oil change 500 mile ago. I replaced the spark plugs not too long ago…

Idk what could be the possible cause of this?

 

Why not post the Evap code? We can't tell if it's a system issue or a leak issue or what if we don't know the code. However, you didn't say you replaced your gas cap. For a leak, this is the first thing to do.

Engine knock could be a bunch of things. I would take that in and get a diagnosis ASAP.

 

P0440- Evap vent control

I did also replace the gas cap. That’s the first thing i tried when the evap codes started

 

Did you replace the evap valve in the gas tank and all the gas tank gaskets?

 

Yes to both.

 

What vent circuit did you replace?

Did you get the complete Charcoal canister assembly with all the valves and hoses?

 

I’m not really sure which one was replaced to be honest with you, but i know it was replaced. Yes the whole assembly was redone

 

If you had a shop do it, have them do it again. They are responsible for fixing the issue.

They need to do a smoke test to find the leak.

They also need to do an EVAP circuit test which tests the valve in the engine bay which can go bad.

 

Yes I’m bringing it back tonight for him to look at it over the weekend. The last time when they did the charcoal canister he had mentioned that the fuel line might need to be replaced too, could that also cause the Evap code?

 

Yes. The Evap system goes from the gas cap to the tank and from the tank to the charcoal canister and up to the engine bay. No leaks are allowed anywhere in that.

From the gas cap, there is a metal assembly and tubing that connects up to the charcoal canister and the gas tank. It can rot out if you live in the rust belt.

 

I’m in NJ so yes kind of in a rust belt lol. I’m hoping that will fix the Evap code because i have done everything else to it.