p0455 smoke test help

[Tannerm]

My 97 f150 4.6 has this CEL. I've replaced evap control valve, gas tank pressure switch and gas tank lid. It still shows p0455. We hook a smoker to the control valve and spent the better of an hour looking for the leak. NOTHING. you can smell the gas while the smoker is running but no smoke. Help.

[Sleeper]

canister partially clogged throwing the code?

My fathers 05 would only throw the code when it rained, or alot of moisture in the air.

[BP]

P0455 just tells you it's an evap problem, not what's actually wrong with it. Fords way of telling you to take it to a dealer. There are 84 different function tests for this code.

[Tannerm]

The canister sylenoid was removed and cleaned out. Then we put power to it and saw its piston activating...
Sleeper u mention the canister being clogged. What do. U mean and how do u cure this?

[JimD]

HX44 - DTC P0455: Visual Inspection For Substantial Evaporative Emission System Leaks
Continuous Memory Diagnostic Trouble Code (DTC) P0455 indicates that the Evaporative Emission (EVAP) control system detected a large leak or
no purge flow. Possible causes:
- After market parts and accessories nonconforming to the EVAP system specifications.
- Damaged, missing or improperly installed fuel filler cap.
- Blockage in fuel vapor hoses/tubes (EVAP canister tube, EVAP canister purge outlet tube or EVAP return tube) in EVAP system.
- Disconnected or cracked fuel vapor hoses/tubes in EVAP system.
- EVAP canister purge valve stuck closed.
- Canister vent (CV) solenoid stuck open.
- Fuel tank pressure (FTP) sensor malfunction.
- EVAP canister leaking.
- Fuel vapor control valve tube assembly blocked.
- Fuel vapor vent valve assembly blocked.
- Check for missing fuel filler cap. If the cap is loose DO NOT DISTURB EVAP system.
- Verify that both the input port vacuum hose and EVAP return tube are attached to the EVAP canister purge valve.
NOTE: If the EVAP canister-CV solenoid assembly is not accessible to perform the following step, Go to the Powertrain/Engine Group, Evaporative
Emissions Section in the Workshop Manual for removal and installation procedures.
- Verify that the CV solenoid is properly seated on the EVAP canister (if possible).
- Visually inspect for disconnected or cracked fuel vapor hoses/tubes between the intake manifold, the EVAP canister purge valve, the EVAP
canister, the fuel vapor vent valve assembly and if applicable the fuel vapor control valve tube assembly.
- Check for damage to the fuel filler pipe and the fuel tank.
Is a fault indicated?
YES CONNECT or REPLACE fuel vapor hoses/tubes as required. REPLACE damaged EVAP system components as necessary. REFER to the
Powertrain/Engine Group, Evaporative Emissions Section in the Workshop Manual for the removal and installation instructions of fuel
filler pipe, fuel vapor vent valve assembly, fuel vapor control valve tube assembly, EVAP canister purge valve, FTP sensor and EVAP
canister-CV solenoid assembly. GO to HX45.

NO GO to HX45.

[Tannerm]

OK I'm at my wits end with this fucking cel.... Super irritated. Again! To reiterate what's been done. Eval vale in the engine bay (on firewall) replaced. Doesn't leak. Fuel tank pressure sensor (above tank), replaced. Evap canister sylenoid removed cleaned, and power added to it. Piston actuated. Works. Smoke tested twice, several months apart. This mother fucker doesn't leak anywhere. The code specifies gross evap leak... Yet it doesn't smoke at all. Gas cap replaced twice. Hoses are old and dry rotted (pulling the hoses off that canister sylenoid made my hands as dark and night). But, they aren't cracked or leaking...

My apologies. It just sucks. CEL on at all times.. Irritating and embarrassing. Someone once mentioned the charcoal canisters might be clogged??? How do u unclog the two canisters? I'm open for any suggestions. Thanks!

[Tannerm]

canister partially clogged throwing the code?

My fathers 05 would only throw the code when it rained, or alot of moisture in the air.

Its been on for two months on. No break in illumination. Bitch is shining bright!

[JimD]

No way i know of to unclog it. I just did one for a good customer, he had been overfilling the tank for years(99 corolla). my theory was lil fuel spilled into vent hole and compromised the canister. One of those deals where its not obvious broke, but replacing fixed it. Shopped around and got him good deal on new one.....and made some dough myself.

[Tannerm]

This thing takes 2 canisters. Lol I assume they ain't cheap either.

[Tannerm]

Also, I searched autozone's website for a "charcoal canister" "evap canister" or just plain "canister" and nothing came up resembling a charcoal canister. Help would be great.

[slow84lx]

Time to hit up a salvage yard for some parts.

[JimD]

Also, I searched autozone's website for a "charcoal canister" "evap canister" or just plain "canister" and nothing came up resembling a charcoal canister. Help would be great.

Hit up ebay, got oem toyota canister $100 cheaper than local dealer wanted.