Po453 engine code

[Zoom63]

2006 Navigator throwing a po453 code and won’t pass inspection. Replaced fuel tank pressure sensor, purge valve, vacuum canister and still throwing evap codes. After having fuel tank out for the third time to blow out all lines, I noticed I can’t blow air into the roll over valves. Assuming they are bad, is there any replacing them. They appear to be bonded to composite tank. Thanks in advance

 

[whtbronco]

So I don't know if the roll over valve is replaceable. I never checked when I had mine out. It can be replaced on some Chevy tanks that I know.

I also doubt that's the issue. I mean if you remove valve the fuel cap is seal is gonna hold the pressure anyway and it likely is now. I don't think the roll over valve seals very well.

I'd look at the wiring for the pressure sensor if you have not. A voltage drop test would be a good place to start I think.