My check engine light is on. I have had this problem since I bought the truck about 6 months ago. Sometimes, maybe once every 15 or 20 times I start my truck, the truck will backfire after I drive it for about a 1/10 of a mile. It will backfire so much that I have to put the truck in neutral, turn it off, turn it back on, and put it back in drive. Then I dont have the problem again for another 15 or 20 starts. I have no idea what the problem is but I have replaced the rear cat converter (there are 3 cats total, 2 front and 1 in back), had a tune-up, and sea-fomed it twice to try and remove all the carbon build-up. STILL the truck backfired again this morning! The check engine light is still on and when I read the codes it says that the front cats are inefficient/uneffective or whatever you want to call it. But I dont want to replace the cats until I find out why it is backfiring in the first place. Please HELP!
have the same problem?
Saturday, February 20th, 2010 AT 8:25 PM