hi monster, welcome. i have a pioneer 202 as well, and have found a bunch of good stuff with it. dig all repeatable signals, and keep digging til' you find your target. brown spots are purty much the norm, and difficult to avoid. an old timer i know buys the cheap fertilizer, mixes a tbsp. or two to a gallon of water, and soaks his plugs down. it does help the grass. rain helps too.
'course now, you don't want to be detecting very many manicured lawns. the owners are just too picky. avoid them like the plague.
the 202 is a great machine. if the signal blows your headphones up, it's big and near the surface{ usually canslaw or a poptab} if the signal has broken up edges, then it's usually junk. you want small, smooth beeps. that's with any detector. you really should go on and dig all good signals, because the 202's range is limited like 99% of other machines.
i like to run my sens. at max if ground conditions allow, and disc. at 9 o'clock. that way, i'm not missing anything. you need good headphones too. if the machine starts chirping, turn your sens. down until it stops and continue hunting. just means you hit a patch of "hot" ground. dig all your whisper or faint signals too, theyr'e often deep coins or relics. good luck, and hh,