My 00 excursion v10 tail pipe is pretty black. I replaced cop and plugs all motor craft and a new motor craft airfilter. Seems to run good. No codes. I am thinking of seafoaming the gas and intake on it

 

if you do have an issue with running rich, I personaly dont think you do but any things possible, the cause's of your problem would be the maf and oxygen sensors, theres also the possiblity of a jammed injector, you'll need a good tunner to check the short term fuel trims to see if theres a problem.

 

Do NOT seafoam it just because it's running rich.

Clean the MAF - if the MAF is dirty, it will run richer than normal.

 

What's wrong with sea foaming?

 

I don't know about sea foam, but if you clean the MAF and it doesn't do it I would think it is a oxygen sensor(s).

 

if it ain't broke, don't fix it - try everything BUT that stuff first.

MAYBE if you were going to add it to the fuel, and burn it, but that "stick the brake booster hose in it and run the engine" thing, well, that's just crazy.