Mate, what do we use in Japanese Variant of Honda CR-V 2.0 Sport k20a4 engine type? Which grade engine oil? I've been using 5W30 Idemitsu API SM grade. I'm thinking to go down to 0W20 API SN, ILSAC GF-5 fully synthetic Idemitsu for this VTEC. Would adding stp fuel line and injector cleaner along with regular flush and engine synthetic base STP additives do harm?
Remove, and install a new filter, along with a clean gasket plug.
Check crank shaft seal (front/rear) and Head cylinder seal areas. Apart from that visit the dealership. Something as minor as an oil pressure sensor could also do that. Again your best bet is to go to a trust worthy auto shop by reviews or a well established and rated dealership. Any place else you'll increase your chances to be cheated.