[jdmccright]

I'd do the compression check as Huney suggested. It's not hard and you can usually borrow the gauge from your auto parts store. Remember to pull off all the plug wires (or the coil-on-plugs) first...you just want to crank the engine over for a second or two to get your reading. Note the max pressures for each cylinder, they should be pretty close to each other +/- 15%. If one or more is noticeably low, pour a tbsp of oil in the plug hole and retest. If compression improves, the leaking is coming from worn piston rings. If not, it is due to worn valve stem seals.

Also as suggested would be to see where oil is coming out of bad seals by tracing oil drips from the bottom to the top. It helps to be able to power wash the engine (while it is cool!) to remove any built up grime & oil, then watch for fresh leaks.

Common leak areas are camshaft cover gasket, oil pan gasket, crankshaft/camshaft/oil pump seals (located under the timing belt cover), and less possibly the head gasket or rear crankshaft seal. Finally, if it is anything like the 2.2L 5s-fe engine, there are a couple of o-ring seals that are under the oil filter where it threads onto that have leaked oil for me once before. Good luck!