2000 mustang

Right about a month ago, I purchased a used 2000 Mustang 3.8L V6 coupe. I got it for $600 bucks (a steal of a deal), knowing full well that the car needed new cats and a new exhaust system entirely, especially since the car is 19 years old now. After I brought the car home on a flatbed...

So I had to drop a new motor into my 2000 mustang gt. The engine is from a 2005 crown victoria. The engine ran perfect when we got it. We got it into the mustang and hooked everything up but now when we started it, it idles at 700 rpm then will jump to about 2000 rpm and will stay there. If we...