I have a 2000 Cadillac Deville. First problem started a couple weeks ago. Check engine light came on for P0446...evap vent solenoid. I'm a semi-experienced mechanic so I know how the system works. I took out the evap vent solenoid under the car and also the purge solenoid on the intake manifold. Sprayed them both out with compressed air, and supplied 12V+ and ground to both from a battery. They both work, and the valve fully opens and closes when the power is supplied/removed. So I put them both back and cleared the code. Came back a few days later. According to Cadillac, the 2002-2005 devilles all had a recall for the Fuel Tank Pressure Sensor. So I replaced it and reset the light. Stayed off for about a week (longer than normal). A week later, I get a CHECK GAS CAP message on the Info screen. So I replaced the gas cap. No change to the message. Then the light came back on again. I ran the code. NO MORE P0446 but now I have the P0440, which is known as the gas cap leak and usually triggers for a big evap leak. Took the solenoids out again, made sure they closed and opened still, then reset the code....came back in 3 days, same P0440 and same CHECK GAS CAP message. Tried changing gas caps again and resetting the code...no help.
So just when I think im dealing with a large leak in the evap system, I go to get gas today and as I'm filling up the pump clicks off numerous times. Then as I remove the nozzle, the gas actually spurts BACK out of the filler hole all over me. Clearly the fumes from the tank are not being properly vented.
So I now have half the signs of a Large Evap leak and the other half is telling me that the Evap system is clogged somewhere and not venting properly. Which one is it? Should I blow out the evap canister next? How can I be getting an Evap Leak code and at the same time get signs of the evap pressure building up too high because of a clog or stuck solenoid? Any help or direction on what to try next is greatly appreciated. Thanks!
So just when I think im dealing with a large leak in the evap system, I go to get gas today and as I'm filling up the pump clicks off numerous times. Then as I remove the nozzle, the gas actually spurts BACK out of the filler hole all over me. Clearly the fumes from the tank are not being properly vented.
So I now have half the signs of a Large Evap leak and the other half is telling me that the Evap system is clogged somewhere and not venting properly. Which one is it? Should I blow out the evap canister next? How can I be getting an Evap Leak code and at the same time get signs of the evap pressure building up too high because of a clog or stuck solenoid? Any help or direction on what to try next is greatly appreciated. Thanks!