Engine Code has me wondering!!

[cmoore]

Okay, I briefly touched on this in my post reguarding a T.C. question but I figured it best to start a new thread. I have had a CEL on for a bit now and I had it checked once and reset. It obviously came back on and I had it checked again and had Autozone give me a print out. Here are the results!

Code: P0455

Diagnosis: "The PCM determined that a large leak exists in the evaporative emission control system."

I asked the guy what this means and he pulled out a book and rattled some stuff off that didn't help. (Like..."tighten your gas cap") Any thoughts on what this could be?? Still possibly an EGR situation?? Thanks again!

 

[Red Devil]

There was/is a leak detected in your evap system (it's the fuel vapor recovery system), you could have a bad gas cap, the charcoal canister mey be toast or not purging properly or something along those lines.

 

[Mr. SHO]

Check the gas cap. It's probably unscrewed.

 

[cmoore]

I checked the gas cap right away...nice and tight. Is it possible for that to really go bad?? Where is the canaster located so I can check that thing out?? Sorry for all the questions!

 

[SHOZ123]

The canister is under the trunk floor. With some nifty bolts that Ford use that will not come out....


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.

The vent solenoid is on the firewall on the passenger side. it has a large hose running to it. If you have some data monitoring software you can see the fuel tank pressure voltage reading and verify whether there is a leak or if the solenoid is sticking on.

 

[cmoore]

Whoa...now that is intense, I will check out the canister and see what I see, I will let ya know! Thanks again again!

 

[cmoore]

I was able to check out the canister (those bolts were a pain) and everything looked good. Now I know that does not necessarily mean it is good but...going to head over to Murray's and see if they have a gas cap, just try that, I am still open to more suggestions though!

 

[Muck]

Thank Goodness

Paul, Thanks, for all the help & information you share helping fellow carguys with SHO Disorder. I really appreciate you! Chuck Minnard