Running rough and white smoke

[Jutt12]

So long story short this past weekend I replaced a faulty 02 sensor, the emdf (or whatever is called) sensor on my 97 explorer, v6 4.0 ohv engine. Go to work monday and she runs just fine, get off work and I've got no spark. So spark plugs, wires, and a new ignition coil later she starts back up. Now she's running rough and has some white smoke coming from the exhaust. The smoke may be because I added too much oil when changing. But I'm looking for ideas on the rough running, she's got 153k miles on her and I bought her from a private seller and have no clue the last time a lot of basic maintenance was done. I've got no check engine light so I'm thinking things like fuel filter, or dirty injectors, or throttle body needing to be cleaned or a combination off all those and other small things. Just looking for some other ideas that others might have or any known issues they know about. Thanks Justin

[shorod]

Welcome to the forum!

Is the white smoke present the whole time the engine is running, or maybe only upon startup or for the first several minutes after starting it from sitting overnight? If it's present all the time, you should keep an eye on your coolant level an pull the spark plugs to see which one appears to be burning much cleaner than the others. Coolant in the combustion chamber is very effective at burning away carbon.... That would also explain the rough running.

Also, I suspect it was the DPFE sensor that was replaced.

-Rod

[Jutt12]

Its not there at all times...i start it up and it pours a bit of smoke then stops after a few minutes. I didn't think about that thanks. and yes...DPFE sensor...i just can't remember those four letters for some reason.