P0442 help please

[Jaredjeandron]

So a couple years ago I got a P0442 code and replaced the Vent Valve solenoid (under the cab near the charcoal canister) and I replaced the gas cap. Seemed to fix the issue and there was no more code using a Bosch OBD 1100 scanner. Fast forward to this last week I got a "pending" "confirmed" and "permanent" code all for P0442 (small leak in evap system). I found both "heater hoses" on both sides of the vent valve solenoid had cracks so I replaced/cut and pulled from slack and fixed those. Cleared the codes but still had the "permanent" code even after driving 50+ miles. Then I replaced the purge valve solenoid on the top of the engine and checked all the other hoses. Drove for another 50+ miles and still have the permanent code. I checked the purge valve solenoid when the engine was cold, popped it off entirely and tested the intake side with a mighty vac and it did not hold a vac at all. I drove around the block and warmed the engine up and the purge valve solenoid held a vac after that 20"Hg. I had to replaced the fuel pump due to pressure drop so that's new as well (including the fuel pressure sensor). I've checked all the hoses and connections to be good, non corroded and everything is hooked up as it should be. I don't live in the rust belt so there's no damage from salt and filling up the truck with gas is normal so it's not a blocked vent valve canister. Any ideas? Evap Vapor Pressure (purge command at 22%) is showing -0.08
 

[swathdiver]

On 5/12/2021 at 4:17 PM, Jaredjeandron said:

So a couple years ago I got a P0442 code and replaced the Vent Valve solenoid (under the cab near the charcoal canister) and I replaced the gas cap. Seemed to fix the issue and there was no more code using a Bosch OBD 1100 scanner. Fast forward to this last week I got a "pending" "confirmed" and "permanent" code all for P0442 (small leak in evap system). I found both "heater hoses" on both sides of the vent valve solenoid had cracks so I replaced/cut and pulled from slack and fixed those. Cleared the codes but still had the "permanent" code even after driving 50+ miles. Then I replaced the purge valve solenoid on the top of the engine and checked all the other hoses. Drove for another 50+ miles and still have the permanent code. I checked the purge valve solenoid when the engine was cold, popped it off entirely and tested the intake side with a mighty vac and it did not hold a vac at all. I drove around the block and warmed the engine up and the purge valve solenoid held a vac after that 20"Hg. I had to replaced the fuel pump due to pressure drop so that's new as well (including the fuel pressure sensor). I've checked all the hoses and connections to be good, non corroded and everything is hooked up as it should be. I don't live in the rust belt so there's no damage from salt and filling up the truck with gas is normal so it's not a blocked vent valve canister. Any ideas? Evap Vapor Pressure (purge command at 22%) is showing -0.08
 

There are smaller lines which it seems you have replaced them and there is a much larger one that I do not think you have replaced.  Also, the parts you replaced previously might have worn out. 

 

Purge valve is under the truck and the vent valve is on the motor.  

 

I've been ignoring mine for a couple of years now.  It sets near the end of each tank of fuel and I just kept resetting the CEL with my Tech-2.  Finally, bought a bunch of replacement parts to fix it but they haven't been put on yet.  I decided to spend the money on shotgunning the parts instead of buying a smoke machine, less expensive if I get it right!