Yes the MAP can cause this but GM has designed a fairly reliable MAP sensor that rarely fails. What usually fails on the MAP is the vacuum line going into it. Check that out.

Massey

 

Just discovered when I removed my map sensor that one if the three wires appeared to be clipped and end stripped. So I investigated and discovered all three wires had been clipped at one point and each individual wire was just twisted back to its wire it belonged to one wasn't even attached. Had not been soldered back, nor crimped just twisted not even taped well. I'm gonna solder them back and put heat shrink on and see what happens. I will post the results.

 

So I soldered the wires back together and put heat shrink on them and then taped them up nice and tight. Seems to be running correct now. It is not with the rough idle like it has an aftermarket cam any more. Unfortunately it is still running a bit rich. Possibly my o2 sensors need to be replaced now. I put a video of it on my YouTube page. You can see it by searching mustangjoe88 on the YouTube page I will post the results of my next fix once its completed. Can anyone tell me what my correct rpms should be at? I'm currently at 1000rpm which I think might be a tad bit high but I'm not sure. Is there any way to test my egr?

 

I think that no matter what you do you will have a strong exhaust smell with the cat removed.

 

Thanks mikey. Mabey I can get my hands on a used cat or something and put it under there. Or take it to an exhaust shop and get a cheep aftermarket but like an oem style replacement type.