Hi all,

My dad's 2000 F150, 4.6 engine threw the P0455 code. My book says this "Evaporative Emission Control System Leak Detected".

We reset the code once but it came back. We would like to fix it but have no idea where to start.

Any help would be great!

Thanks,
Tom

 

It's a fuel system leak code/Evap system not holding pressure.

If you're lucky, it will be a loose fuel cap, the result of fueling while the engine is running, maybe a loose or cracked hose leading from the fuel tank to the filler neck. If you can't find the leak yourself, best bet is to bring it to a Ford dealer. They will run smoke through the system to locate the leak.

This can be a rather difficult one to track down on your own.

 

I just fixed that same problem on my 98. Check between the battery and firewall. There is a vacumm line connector with 3 small and 1 large vacumm line. Mine had chaffed against the battery and wore a hole in 2 lines. After repairing the lines and resetting the computer all is well now.