I have two P0440 codes reading on my 2001 Chevy Blazer. People say it is the gas cap, but i havent had to get gas in like 2 weeks (don't drive often). I had some type of emissions pump go out on me back in december, and that was replaced under warrenty. The P0440 code is Evaporative Emission Control System Malfunction. So, is it my gas cap leaking, or do I probably need another one of those pumps, or something completely different.
Also, lately I have been getting a knocking noise when I start the Blazer up. I only use 89 octane in it, am I still getting engine ping with 89? Jesus this car sucks so far....