Got a tune up on my 2000 Ram 1500 5.9 and 3 weeks later check engine light came on. I brought to the dealership and it flashed P0442. They smoke tested it and found leaks. Replaced all the lines from the leak detection pump to the vapor canister. Also replaced vapor canister. Re-smoked it and nothing. 3 days later light is on again. Ended up replacing duty purge pump. Also replaced leak detection pump. 2 days later light is on code P0443. Can a tune up cause code P0443? This has been a month now and driving me nuts.

 

did you replace this?

http://www.autozone.com/autozone/par...er=364511_0_0_

 

That is the duty purge pump and yes.

 

be aware that it takes 2-3 days for the leak detection system to trip the CEL after its been reset.

its probably a vac line (or split end), and could be any of the ones from the leak detection to the canister to the gas tank.

check the large u-shaped hose between the 2 canisters. see here.
https://dodgeforum.com/forum/2nd-gen...-leak-fix.html

 

All the lines and vapor canisters have been replaced with new mopar parts. The code p0443 shows is an open circuit. It has been back to the dealership 3 times. Now they are saying they think it is a wiring issue. They said it could be some kind of open circuit at k52 evap emission solenoid control and f12 from c4 junction block to pin 2 at purge solenoid connector. Found high resistance (open circuit) when wiggled at circuit k52. Wiring needs to be replaced. I don't know if they are blowing smoke up my butt just to get rid of me.