Pontiac Repair: I am working on a friends..., pontiac sunfire, 2000 pontiac sunfire

Question
I am working on a friend's car. It is a 2000 Pontiac Sunfire 2.2 engine. I replaced the oxygen sensor a week ago because I got the trouble code for it. It was also giving the trouble code for P0440 before that for a malifunction in the EVAP system. The oxygen sensor code is now gone but the 0440 came back. She says she clicks the gas cap all the way when she gets gas, and also says that she gets a light on her dash for "traction off. " Can you help me determine what the trouble code 0440 would be for and if it is related to her traction off dash light?

Answer
P0440 is a gross EVAP system leak. More than likely your friend has a bad gas cap. Even if she's putting it on correctly, and hopefully not filling the tank while the engine is running, this will cause headaches. If this doesn't solve the problem then you will have to take it to a shop that has an EVAP leak tester specifically for 1996 and up systems because they are low pressure and easily blown out otherwise. As far as the traction light, they shouldn't be related at all and this may be another issue of it's own. Hope this helps and good luck :)