This post is about my '03 SS and is also posted on SilveradoSS.com

For the last few months I've been having an issue with my truck that I can't figure out.

The symptoms are dramatically reduced mileage (about 25% less) and about 10-15% more throttle required to do everything at light loads. When I'm driving around town light acceleration seems to take slightly more throttle and and I hear the intake growl all the time now. My favourite slight grade going up the street to my home use to be light throttle all the way up. Now it's alittle more throttle and a downshift. It's almost like I'm pulling a small trailer around and the truck is loaded down. On the other side of things full throttle performance doesn't 'seem' to be affected. One of the reasons I posted this is I just found out today a loud rattle I've had for about the same amount of time is inside one of my cats.

My Loud Rattle
http://www.silveradoss.com/forums/in...4&#entry706304

This I've done lately to try and fix this:

New Air Filter
Cleaned MAF and TB
New plugs and wires
New fuel filter

My truck has only 50,000 miles on it so I'm alittle annoyed.

Thoughts anyone?

Regards,
Dan

 

Well I would say your cat is plugged. You should check the one that is rattling, I bet that's the problem.

 

tap your cats with a rubber mallet, if they're shattered, that will make them rattle. i've been having a similar problem with my gas mileage lately, and i blame it on the ******* ethanol in the gas.

 

Time to port and polish the kitties.

 

I was thinking cat before I finished the first sentence.

 

Blew a misfire in cyls 2 and 6 (right side) today at WOT. At first the dealer wasn't going to replace the right side cat but after the code they relented.

Regards,
Dan