Hi,

My name is Denny, I have a Chevy Silverado 04.

Upon starting up, after 7 miles, it loses power and won't go over 30mph. It's a 1500 5.3 V8 2 wheel drive with throttle body. About 165K miles. Two different auto shop expensive scanners gave no codes. It does not sputter like a plugged up cat converter. Also has fresh gas. If it sits for a while it runs fine for another 7 miles then does same thing. It also idles smooth. All suggestions and ideas greatly appreciated. to solve this problem.

Thanks for anyone's help. Denny