codes contradicting each other?

04 rx8 130k. I got a few codes bank 1 lean cleared code. Then bank 1 misfire. Very heavy white smoke only twice within 2 months, smells like fuel no sweet smell. but not while codes come up. After driving from tx to ca made it to ca Driving at 4500 rpm. push gas peddle while driving. engine slowly revs down to 0. Would not start. After 10 min it would start and run fine no smoke. new spark plugs 2 weeks old, coil packs 1 year old. Car sounds like an exhaust leak at high rpm under load. Took it to two different exhaust shops. Both said they think it's coming from the engine. resonator has been removed. Aftermarket generic cat not gutted 1 year old. Oil is a little above full. Not full enough to be a concern I think. The dealership is lost. They just say replace the engine, coil packs, spark plugs, and wires.but can't tell me why. Spark plugs are brand new. They say because of the white smoke. No compression tests were done. Could this be an injector malfunction?