Mass air flow ? missing when it snows out

[sueslimited]

Have 02 4.6 explorer when it is snowing engine misses and runs rough when stops snowing runs ok could this be mass air flow or has anybody else had similar problem/fix

 

[Exproblems]

Have 02 4.6 explorer when it is snowing engine misses and runs rough when stops snowing runs ok could this be mass air flow or has anybody else had similar problem/fix

No, not Mass Air Flow sensor. That is sealed inside the air intake tubing just past the air filter housing. Sounds more like a moisture issue with your spark plug wires from a crack in a spark plug wire boot or the wire itself and wet weather causes moisture to get on the plug wires which shorts out the spark causing a rough engine condition. Check or have the spark plug wires checked by someone, looking for cracks in the outer insulation. If you find a bad plug wire, I would replace the whole set of them using "die electric grease" in the boot ends when connecting up the new plug wires. The grease seals out moisture at the boot ends.

 

[sueslimited]

This is a coil on plug engine no plug wires

 

[Exproblems]

This is a coil on plug engine no plug wires

I have the V-6 engine with plug wires and I'm not familiar with the coil on plugs for the V-8 you have, but your problem still appears to be 'moisture" related where your "spark" is being interupted by the snowy wet condition. Your MAF sensor should not be getting wet.

 

[n2epv]

Had the same issue with my '04 Ex 4.6... problem was two coils shorting when moisture condensed under the hood. If you are getting a 'check engine' light, get the codes read, and it will tell you which cylinder has the bad coil.

It's an easy swap. Just be careful when replacing the bolt that holds each coil in - the threads go into brass inserts in the intake manifold and are easily cross-threaded. Don't forget diametric grease on the boot (a small tube of grease came with the replacement coils that I got).