i got a 94 ex coupe all stock auto d16z6. when i got it the headgasket was blown and a spark plug hole was striped. so i pulled the head and helicoiled the spark plug hole put a new headgasket and the car runs fine but it has no power at all the low end is horrible its slower then a dpfi motor. everything seems good on it the motor seems a tiny bit shakey at idle some times. any ideas?