I have a 93 dakota w/318. It suddenly will not idle, is much louder than before the issue, & there is a huge loss of power... At 1st I thought, "exhaust leak..." then possibly a bad "MAP sensor..." From what I have described, does it appear that I'm on the right track.., & where to go from here?

 

Possibly a bad O2 sensor or a vacuum leak.

 

I checked the computer for codes. I got 12--13---55. If it were an issue w/the o2-sensor.., I have to assume there would have been a code? As for a possible vacuum leak, I'm not sure... How many places could there be for a vac-leak, & how do I check/diagnose this? I really appreciate your input.

 

Code 13, (no change in MAP from start to run) I assume this abnormal.., but what are the possibilities that could be the issue when this code comes up??