I've done a couple of searches on this but seem to find really mixed responses. I have a '99 Accord EX I-4 which runs fine, but the valves are just a little bit noisy so I figure I'll do a valve adjustment on it since it's got 101K on it anyway. I read on this forum about seafoam which can clean up some of the carbon and sludge buildup and thought it couldn't hurt to try it. But I read that it can jack up your O2 sensor, CAT, and other things. Well hell if I want to replace a bunch of equipment just to stop a little clicking, that if I weren't so dang picky I probably wouldn't even notice. Any opinions on this? Should I maybe just apply to crankcase and not to fuel system to avoid some of the problems I might encounter like the sensors and what not?