My 04 3.7L Dakota is throwing 2 codes P0498 and P0499. I read them with an OBDII reader and it came up EVAP emission vent vlv/sol malf circuit low and the same except high. I was told it was a vacuum sensor for the fuel tank or a bad gas cap. I cleared the codes andit threw them againimmediately whenI started it. This makes me think that it is not the gas cap, but I dont know where that sensor is located. If anyone can help it would be much appreciated.

 

moe in wichita ks
last fall i traded in my 99 dak for a 01 dak. i had a locking gas cap on the 99 so i put it on the 01 and got error code. seems that the 01 uses a different gas cap, and that kicked out a error code. had to buy a new cap. so double check that you have the right cap. also check evap system hoses. pcv valve?