A neighbor with an '04 DII asked me to read an SES light code today. Plugged in the Hawkeye and the only code was P0455.

The P0455, according to several threads, here is often caused by a fuel cap not tightened appropriately or not sealing well. I've read that if addressing the fuel cap doesn't correct the problem replacing the purge valve may solve the problem.

But here's the question - when I searched the RAVE the P0455 code was not found, even though as I said there are several threads on this forum about the P0455 code. Does anyone have a good explanation about why P0455 is not described in the RAVE?

 

P0445 - Canister purge valve fault (power stage) Drive cycle C:Signal out of range - belts


i just went through this. I’ll do a bit of what I did later on Today

 

Thanks. I understand what the code is, and what it means. I'm just a little baffled that it's not included in the RAVE.

 

p0445?

 

Thanks. I'd overlooked that redwhitekat cited a different code.

The one I asked about is definitely P0455, not P0445.

 

P0455 is an EVAP leak code. Large leak

"DTC P0455
Evaporative control system - large leak detected Drive cycle C:Signal out of range - below minimum"

As for chucking a purge valve at the problem, thats not likely to help you out. Generally if you had a bad purge valve the EVAP system would detect that and you would fault out for it, and you would usually have a LEAN code as well. I would be performing a smoke check of the evap system

 

@Llamasayswhat I've never done a smoke test before, but I picked up the parts to make a setup at one point, so I could assemble a tester. Could you advise what and where you'd test to try to isolate the large leak P0455 code? Would it be testing by blowing smoke into the intake? Around the engine to see if the smoke is sucked in to any cracks? Sorry if this is a rookie question.

 

I'm struggling with the same code ATM. I found that the hose from evap line to the purge valve inlet was swiss cheese. I removed it, put my finger over the end and blew into it, and it was if my finger was NOT over the end of it. I swapped in a piece of fuel hose and hoped for the best. Later that day P0455 returned so I swapped in a spare Bosch purge valve of unknown history but the problem persists. This truck does not have SAI and I noticed a test port in the purge line between the back of the intake and the firewall. I looked on one of my SAI trucks and it looks MUCH more difficult to get to.

Here's the port



And here's a closeup of the label on it.



EDIT: This guy makes a great case for NOT using the factory port.

 

anyone know if the onboard ECU on a D2 with the 4.6 allows you to set the purge solenoid valve open/closed via a scan tool on the OBD2 port?

I have an Autel 619 scantool. This is for performing a smoke test of the evap system.