My truck has a 5.3 for an engine. The problem I have is during cold weather temps it idles very poorly and the sevice light comes on. We scanned it and the codes came up as abad o2 sensor and a bad mass air sensor. I replaced both with no change in the idle. During warm weather temps ( ie above 40) the light goes off and the truck runs just fine. We scanned it a couple of times and the codes come up the same. The truck runs fine a hwy speeds but very bad at idle.
Jan 27, 2009 at 7:55 PM