I noticed a few weeks ago that my tail pipe was running a sooty black
and after some consideration have went into the adjustable parameters
on the SCT II and did a minor spark advance with a one step leaner
mixture on the 87 tune. It seems to have perked it up a bit, and haven`t had any trouble codes. I do a lot of short distance city driving back and forth
to work, and wouldn`t use this on a long haul hiway drive.

The question is has anybody advice pro or con on doing this?
I`m going to have a look at the plugs here shortly and see what they tell me.