Yeah, it's on the back side of the M90, mounted upside down. The vacuum line from the T under the snout routes to it.

Seafoam will clean carbon from the intake/valves/cylinders but not the EGR. Only thing you can do there is manually remove it. It's hooked directly to the exhaust and on older cars, built up chunks of carbon from the exhaust break loose and just get lodged in there.

IACs can go bad, but it's rare. Might try removing it and cleaning it and the hole it sets in, along with the throttle plate. It can't hurt. Carb cleaner and a toothbrush is all it takes.

I'm about to start diving back into the GTP game with my '98 I've had sitting for the past year. So, I may be popping around from time to time.