I have a 99 1500 2wd 5.2, on the freeway today I tried to pass someone and the rpms jumped and engine just revved. after this my truck wanted to bog down after giving it gas. I could stay at 70 mph, but when I tried to accelerate at any time my truck would bog down and the check engine light would come on. Also, the exhaust got real quiet.....I have a 40 series flowmaster muffler and now my truck sounds quieter than stock exhaust. I thought that it may be the cat was blocked up....but I have no idea PLEASE HELP ME FORUM!

 

Sounds like the guts from your cat may have let go [>:]

 

Lol, i dont see the forum actually helping, but us members probably can! I second the idea that the cat is clogged. Actually, i put 100 dollars on it. Bad catylitac convertor consist of :

1. Loss in engine performance
2. Quiter exhaust

The only other thing that can affect the engine performance as per exhaust would be really bad timing, however i dont see your timing chain skipping 3 or 4 teeth in order to do that and still be able to run =)

what you can do, is start the truck, and take a temp guage, check the exhaust pipe in front of the cat and the exhaust pipe after the cat, if the temp is higher in the front, you have a problem with the cat. If it isnt, then the cat is fine, but i would be really confused if that wasnt the case, and prolly out of 100 bucks...