had to put on a new alt belt , so I left the smog pump belt off car seems to run better . Question, will this hurt the engine in any way ? thanks.

 

If you have a stock exhaust.. the cat will over heat because it needs air to work properly. If you did that you might as well remove the rats nest. It will not hurt you engine but your chances of passing a smog test are nil.

Worst thing I can think of is your cat's interior stuff will melt and seal up your exhaust then you will be limited to rev under 4000, if thats done for a while you could blow up your engine.

I am not sure of what I wrote, I think thats whats going to go down though. I am sure others can varify or contradict what I wrote.

 

Yep. Either put the belt back on, or take your cat(s) off. Might be a good time to pick up that Racing Beat exhaust system/header...