My wife's 2001 Escape has 175,000 miles. New plugs & coilpacks. Rough idle.. on 2001 Ford Escape

This has been a great vehicle for us but now it is idling rough in the mornings but is ok after warmed up. She said there was an unusual smell coming from the exhaust during the rough idle. Does this sound like catalytic converter gone bad? If so, how much would it cost to replace??

Asked by for the 2001 Ford Escape
might be a head gasket
2 more answers
might be a head gasket
you may have a vac leak after repl coil packs as intake had to come off torepl coils.have a smoke test done 1st to determine if there is a vac leak. do you have any eng codes like po171 and po174?