July 6, 2006I have a 98 Chevy Silverado extended cab half ton two wheel drive with a 5.7 Liter Vortec 350. Right now it has about 145,000 miles on it. With no engine mods. My truck has always run great with a lot of power. No problems since about a year ago when we changed my fuel pump and filter (and some part the distributer, my uncle did it for me, not sure what he replaced ... it may have been the whole distributer). I did plugs and wires in April. My front brakes the first of June and the rear brakes about a week later. The only change I've made lately is I put on a locking gas cap I bought at O'Reillys about 2 weeks ago.
Last Friday the check engine light came on and I don't know why. It's not really running any different, none of the gauges are reading different. The only thing I've noticed is a very very slight loss of power and the exhaust (straight pipe duals) sounds slightly quieter and from time to time I have gotten a weird smell like something getting hot. I think the smell is fixed now, one of my buddies found a rubber coated wire rubbing something at the back of the motor that was getting warm.
I don't know if this is relevant but the day before the light came on I filled the truck with gas. I've checked all my fluids and the belt and the air filter and all the wireing connectors. Its gone just under 3,000 miles since the last oil change but the oil I run is synthetic and can go 5,000 miles (and it usually does). Plus my light never comes on when it needs an oil change anyway.
The guy at O'Reillys told me to unhook the hot wire on the battery for a couple of minutes and it should reset the computer and turn the light off. Tried that, it didn't work. When I went back he told me to change the fuel filter and run some gas treatment through it. I don't really think this will fix the problem but I might try it if I don't get any better ideas.
My uncle is a mechanic at a Dodge dealership and I asked him about it. I told him what it was doing and everything. He said the light was a computer thing and I needed to run a diagonistic on it to find out what it was but if it was still running good then it was probably nothing to worry about. He said to try putting my stock gas cap back on and see if that helps. Something about vaccum and compression, I don't know. Did that Tuesday and still no change.
I do have an small exhaust leak at the passenger side header where there's a chunk of the gasket missing, could this have something to do with it? Someone told me that the cats might be cloged and that could be doing it. How hard is it to take the cats off and check them? Does my truck require cats to run right or can I just remove them and weld in a peice of pipe?
The truck still has the power, still spins the tires and does a burnout like always ... all that stuff. I just have this annoying light and I want to know why it's there and get rid of it. If anyone has had this problem let me know, any ideas would be appreciated. Thanks.