P0440 code

i have had the code come up in the past and cleared it and it would intermittently come back. Sometimes in a few days sometimes in a few weeks but this last time it was actually a few months. Of course it is becoming an issue now again because I am in the process of selling it. The last time I cleared it I made sure not to fill the tank all the way and that seemed to keep it off, but between then and now I have filled it all the way quite a few times with no issues. So thismorning on my way to work I get right to 1/4 tank and it comes on again. The last time I put gas in it was about a week ago. If I kept it off for so long could it still be a serious issue?

 

gas cap going bad?

 

check the vacuum line going from the air box to the VSV that sits behind the battery. Mine was torn at the airbox and not allowing vacuum to the evap system. replaced the line and code went away.

 

Wanted to thank Hossmaster for his advice. I was leaning towards the same idea. My air canister box broke between the rectangular box, and the cylinder tube that heads into the engine. I knew it was sucking air right there. The vacuum line for the VSV connects to the rectangular air box and I bet it wasn't getting enough vacuum. I cleared the P0440 code with my cheap ELM 327 OBDII device, recommend everybody have one, and ducked tape the tube back to the air box (we'll see how well this holds until I get a replacement). Will report back if the code comes back. If I don't report back, assume this solution worked.

 

Check vaccum hoses and vsv valves.
Check the vsv's resistance it should be 30 to 50 ohms
Check the vsv connections for continuity also.

Just two days ago I decided to check the connections after removing the charcoal canister to see if the thing was blocked or cracked, it wasn't, I checked a connection and I had to wiggle it a little in order to get continuity (not voltage) continuity.
I had the CEL showing the P0401 which has to do with incorrect flow, or insufficient flow in the EGR system. It couldn't hurt to check.


Good luck.