2.5L ('98-'01) 2.5L p0445 code

[PatrickBruce]

1998 2.5 5 speed. Truck starts fine, drives fine. It ran really rich for a couple years with O2 heater circuit codes active along with p0172 (rich condition). I replaced both O2's, the codes always came back. Changed pcm to a junkyard one and the O2 codes have not returned. The pcm switch was 3 days ago.

Now I don't smell fuel anymore, but I have the p0172 and a new one, p0445 (evap purge valve circuit shorted). I changed the purge valve, code returned. How should I go about testing the circuit to figure out the short?

Can a shorted purge valve circuit cause the rich condition?

Thanks!

P.S. I'm getting about 17.5 mpg city and 22 highway..I think those numbers should be higher.....

 

[PatrickBruce]

Bump

 

[SenorNoob]

Evap purge could cause rich. IF it's stuck open and pulling fuel straight outta the tank. I'd find the vacuum line going to it and and plug it as a test.

 

[PatrickBruce]

Evap purge could cause rich. IF it's stuck open and pulling fuel straight outta the tank. I'd find the vacuum line going to it and and plug it as a test.

Fantastic. I'll try that. I confirmed last night that the connector for it does have battery voltage. The short would have to be on the switched ground wire to/from the pcm. After I test the purge valve, I may run a new ground wire to the pcm connector and see if that fixes it.