1999 Explorer. Lack of power

[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.

[shorod]

Welcome to the forum!

How much smoke would you say you're getting from "underneath"? Approximately which area underneath? Does it have an odor? What color is it (gray, white, blue)? Are any of your fluid levels dropping? Does it only happen when you are experiencing a lack of power?

Also, just because the check engine light is on does not mean there are no stored or pending diagnostic codes. It would be worth the effort to connect a scan tool that is capable of checking for pending diagnostic codes.

Did the issue start following the tune up and oil change, or was the tune up a result of the lack of power? If it started after, the issue could be a spark plug wire that is not fully seated or just plain bad (somewhat common with "economy" plug wires). It's also possible a spark plug could be cracked, but that often would cause a misfire even at idle and start immediately after the tune up.

-Rod

[goneweekends]

That was my first post I read and I am student for auto-tech.. believe me here in my country it is not common for a female to work like this... I was so impressed at all the questions, I could even follow along that time