I had this code for ever and last night I lucky looking thru fixed it. 1st after watching a video on you tube http://www.youtube.com/watch?v=Dfj-F_pTj5M&feature=fvst it said when you have code p0440 (Evaporative Emission (EVAP) System) means you don’t have enough vacuum.

So I started to look at my vacuum diagram on the car and followed the vacuum line from the throttle body to where it says it should go. And sure enough as I follow the red arrow in pic that vacuum line goes from throttle body to the evap purge valve and the line was not even connected. So I added a new hose to it.

Then I kept on following the other line that goes from the purge valve to the evap service port and then to the fuel tank and sure enough as you see in blue arrows in pic that hose was cracked also.

All this explains why my car smelled like gas and I had the p0440 code. Also at 1st I had replaced the gas cap and it didn’t fix the code. The gas fumes that get purged in to the throttle body where just escaping back into my engine bay and not being recycled thru the combustion chamber as intended.

Hope this helps someone fix there p0440 code as it did for me.

















~1996 Cavalier LS 2.4L (auto)