I have an 05 Vibe. Yesterday I was driving and whenever I would stop the car would knock off. I had some codes showing on a sensor, P420, P441, P4455, P456, P741, and P171. I bought and installed a canister purge valve and the car started right up and was running great. I drove home, stayed for about 30 minutes, drove to work, did something in my office for about 15 minutes and was going to drive somewhere else but the car would not start back up at work. I let it sit for a few hours and it started just fine. I drove home, parked it, turned it on and off a handful of times and it started just fine. This morning I took my daughter to school, stopped and got gas, and drove to work. At work the same thing happened. I stopped at one building for about 15 minutes, went back out to my car and it would not start. I went back an hour later and it started back up. Any idea what is going on? Any help would be great.