Smoke test pointers with persistent P0455 DTC

[Grego]

Setting up to perform the same tests on my 2000 4.0 Ranger. Some good stuff on this thread to watch for!
Good job posting the update!

 

[Summers22]

Well 2 months later and 5 tank refills, P0455 is back. Ran another smoke test, no leaks using the bottom hose of the Purge valve that goes back to the gas tank, vapor canister. Used the top hose and had smoke coming from the top of the purge valve, the egr and the IAC vent. I may have to get a diagnosis done at a shop since my scanner is not bidirectional. Are all 3 of those leaks normal?

 

[Summers22]

I just watched a video showing how to test the purge valve (unplug it with engine running and remove bottom hose going to gas tank, if vacuum on the port, its bad) test showed no vacuum, so purge valve appears to be okay. It is a Motorcraft part that I replaced 1 year ago.

 

[Summers22]

Replaced the vapor canister and vapor canister vent valve. No change, P0455 is back. Suspecting a wiring issue. I have good tank pressure, no smoke leaks, working purge valve, new vapor canister, new vapor canister vent valve. Only thing not new is fuel inlet assembly and thats not all that expensive. There were numerous mud daubber nests all over this truck when I got it. Wondering if the fuel inlet tube is clogged. May replace it and if thats not it, pay my local Ford dealer a $109 diagnostic fee. I did try to bend back the flapper on the nozzle hole as it was bent slightly open, got it pretty sealed back up flat if that makes sense.