Hi all
2004 Dodge Ram 1500 4.7l 2wd
I had a few codes last week 0456, 0455 and another I can't recall. All related to the Evap system
Had a mechanic check it out and he said it was the LDP as it was showing no change in flow through it even we he unhooked the vac line
So I picked one up for $60 and installed. Cleared the codes and now I have a P0440 code. That's a complete system failure I believe?

Any idea why? Did I install something incorrectly?

Any help would be appreciated
Cheers!!

 

http://www.obd-codes.com/p0440

 

Most independents can't run a forced monitor test on the evap system. If testing blindly, you have to be creative to force the system to do something and most of the time your results are faulty. Most of the time it's either a cap or one of the hoses has a big crack in it, mostly by the canister. If there is a hole somewhere, the NVLD will not change states no matter how much or little vacuum is applied.

 

Well replaced the LDP and the check engine light finally went away. Took about 4 days of driving but it's gone
Any idea how long it takes the codes to clear? Or do I need to clear with a battery unhook?

 

I read on here somewhere that it does take a few days for the codes to clear after a fix/repair. The evap system does a check whilst the truck is parked up to make sure there is no loss of vacuum. I had something similar, new gas cap, checked all hoses and joints and the engine management light was lit, day or so later it went out after initial start up.

 

Two Trip Fault. Three good trips to turn off the MIL.

 

Depending on the manufacturer could take up to 1000 key cycles to clear a code.