"Actually you want the switch plugged in but you may find that moving it so that the throttle arm does not touch it improves the top end."

That's interesting. I think my current problem is leaning out at the top end. So how do you bring the mixture richer, adjust the pressure?

"Your not missing anything else really...just have the mechanic get it all back to stock before you worry about making power. Once it's running well then you can start to tweak it."

Yep, that was the plan. He still insists on having a cat convertor on it in order to get the O2 sensor hot enough. Doesn't the electric heater do that? Or does it need full exhaust heat on top of that?
One option seems to be to move the o2 sensor, as it is shrouded in the big part of the cat shell and out of the direct exhaust blast. Is there a dual-outlet cast manifold with a O2 sensor port? How about a replacement downpipe with an O2 port, eliminating the cat?

I'm getting further up the learning curve - thanks guys.

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