I have a 2003 Dodge Ram 2500 5.7hemi 190k miles and I keep getting a recurring P0499 active code with a P0452 pending code... I know dodges notorious bad gas caps but I'm not entirely sure it's the cap... Wondering what else I could try to get this code to go away cause I would like to have my dash light free again... The codes don't particularly seem to really be hurting anything cause the truck runs like a top original trans and all... Maybe a bad wiring/sensor issue? I dunno I'm not entirely familiar with the Evap system aside from its function.... Any advice would be appreciated

 

Early Gen III uses similar system to the late Gen IIs. Small vacuum pump to check the integrity of the system. Any pinhole anywhere in a line will set a failure code. Believe P0499 is big(ger) leak, or failed purge valve. P0452, which my '03 carries is small leak. I have the factory manuals in print if you need help.

 

Pull off evap system hoses and squeeze the ends. This means under hood and underneath by the charcoal canister (I have a Dakota, so not exactly sure where yours is) If you find any cracks, cut off the end and reattach. Squeeze along hose lengths too... you might find cracks there. I found cracks on mine and fixing those greatly reduced the frequency of the codes, but once I replaced the LDP, they completely went away for good. So I had multiple issues in my case.

 

Once you have the codes, with some thought, most of this can be diagnostic with your existing tools. DRB just simplifies things.

 

hey, where was the LDP in the Dakota located? Getting a p0452 myself and trying to locate it, thanks