05 v6... dropped down from 3rd to 2nd at high rpms,check engine light started to blink car rides rough for around 20 secs goes back to normal but does this every time I get up in the rpms or hold around 3500. Did a full tune-up ,change cam sensor...read misfire 2and 3rd or 3rd and 4th even after full tune-up. What could it be?