I have a 93' its stock other than intake, down pipe, midpipe exhaust. and it idles at 1200-1300 rpms but has a smooth idle. is that normal? and I was wondering if I could have a cat welded into my mid pipe? I was looking for a stock midpipe but mazda wanted $1800 I would rather get an ecu with that money.

 

That's high for an unported motor. Should be down around 850 for a '93.

 

In my mid pipe could I have a cat welded on? because I need a cat from what I hear if I dont have a ecu.

 

You can add a car. Im new to this , so I dont know if no ecu upgrade is bad with all those bolt ons. <opst cars I have dealt with dont have that sort of problem, but I dont know about rotaries. Just get a ecu instead, if its that much better