I have a 97 Mazda Protege 1.5L Automatic. The car starts and runs fine until I get to an intersection and stop while in drive. Then the idle starts to rev up and down. Before it would come close to stalling but never stall but lately it stalls every time I stop for more than a couple seconds. So I've just been putting it in neutral before I stop and then it idles normally. I'd like a more permanent fix though. CEL is on and I get 4 codes in the following order: P0300 (random multiple misfire), P0170 (fuel trim bank 1), P0420 (catalyst system efficiency below threshold bank 1), P0335 (crankshaft position sensor). I replaced my spark plugs and 3 of the 4 were very oily. The new plugs didn't help. I know there is probably many possible problems. Where should I start? Thanks!