One day this truck runs fine, no issues. The next day it turns over but wont start. Sometimes it would sound like it was barely starting to run before stopping. A few days ago I cleared a P0449 code thats been in there since I bought it in the spring of this year. When I scanned it after it wouldnt start it gave a code for MAP sensor, which I replaced. The old one had a grease like substance on it. But the truck still won't start with the new sensor. It seems like it could be a fuel problem, but I can hear the pump with the key on. I read some threads about passlock problems that sounded similar, but I don't get the security light like they did........about the same time I cleared the Evap. code I also replaced the battery. Ran fine for a few days then had the problem.