Hello everyone just bought a 86 mistubishi mighty and it idles rough and smells bad

[SubGothius]

If "smells bad" means a sulfur odor like rotten eggs, that would tend to indicate a bad catalytic converter, which could also explain the poor idle if the cat is partially plugged.

[xboxrox]

If "smells bad" means a sulfur odor like rotten eggs, that would tend to indicate a bad catalytic converter, which could also explain the poor idle if the cat is partially plugged.

Agreed, after all the fixing of ignition carburetor new sensors I'm now searching to get a catalytic converter (when replacing the O2 sensor we saw the cat was 90% plugged..!) Truck exibits lack of power poor gas mileage rough idle black tailpipe and temp gauge gets to 3/4 scale on uphill grades ALL are symproms of plugged cat...
25MPH stop & go driving here which will plug cats ~ gotta heat the cat on the H3 fwy to blow out the crud...