Just a quick inquiry for those of you that are savvy in the ways of driveability. I have an 03 D2. first smoke test showed a vacuum leak on the upper plenum at the brake booster port. fixed it while doing a reseal of the upper and lower intake gaskets to fix that and oil leaks. the bank 1 upstream O2 wasn't doing anything so i replaced it. the one on bank 2 was switching fine. my question is this: there is a K&N filter on this thing so would this hi-flow filter be allowing too much air into the system much like a vacuum leak to cause a lean condition? Also, there was a considerable amount of oil in the O2 connector, and also the crank position sensor (which decided to die yesterday). would this be a culprit as well? with the scan tool looking at the O2s, voltage will move some if you snap the throttle, but bank 1 will go right back to pretty much 0 volts. There are no more vacuum leaks up top and the engine is running good. new coils, plugs, wires, gaskets, oil and coolant. Thanks for any responses!