I seafoamed at night. The whole col de sac looked like it was fogged over. Marine layer type thick. Initially, it'll smoke like crazy but it'll get less and less as the carbon is burned out. Keep the rpm up when spraying. There is a vacuum plug right at the throttle body. That's a good access hole.
Keep a new cat on the shelf for testing. Works every time!

92 Xcab V6 4x4 SR5 5sp., Detroit locker rear, lim. slip front, Warn hubs, H4's, electr. fan, eng. oil cooler, 1 lift, open cat.