We all know the S2k runs rich from the factory. Evidence is the black soot on the tailpipes and sometimes black smoke at WOT. Is there any way to lean out the engine a little (to get better gas mileage ) without having to use a V-AFC?

 

I think it runs runs rich to be safe. Are you sure you want to chance it?

 

there is a reason why it runs rich during vtec...it helps keep the combustion chamber cooler under high rpm use.

 

I've seen posted here that a CAI, header and cat back exhaust can lean it out to some extent. Don't recall seeing any backup proof on this, though.