Chevrolet Repair: Wont rev! Humble chevy s10 4 cyl, muffler shop, chevy s10

Question
Hi, I've got a 97 Chevy s10 4 cyl 5 speed. A rattle sounding like a heat shield developed a week ago. Since then a whistle sound came from the exhaust above 3000 rpm. Now the whistle is gone and it won't rev above 2200 rpm even in neutral. I was about to have it scanned for O2 sensors being out, but a mechanic told me that the Check Engine light should be on - and it isn't. Any ideas?

Answer
Hello Brandon,
Unbolt the catalytic converter from the exhaust pipe, that is, in front of the converter, and take it for a little ride with the exhaust open.
Then go to a muffler shop and have a new exhaust system installed, cause that is going to make it run great.
Don't get a ticket with that disconnected. It will be rather loud.
Van