[explorer78]

I have a 1999 Explorer. 5.0 V8 auto AWD. Motor bogs down when going up hill. Smoke coming from under vehicle. Recently tuned up & oil change. 157,000 miles. No warning lights. Not over heating. No burnt smell from oil or trans fluid. No leaks from motor or trans. Oil & trans fluid look clean. I have a little mechanical knowledge. Someone said it could possibly be a bad catalytic converter. I would appreciate some help before it goes to the shop & money gets spent.