Originally Posted by Hydrolock

I am confused... The misfire that RARELY happens burnt your cat. That just doesn't make any sense to me.

If your car is running fine why are you or your mechanic even considering that a valve is sticking, you would have poor idle quality, in addition to being able to see this problem with a vaccuum gauge. Throwing money at it with reckless abondonment isn't gonna fix anything unless you really have your heart set on doing a motor swap anyways.

1. Are you sure your cat is bad. How do you know?
2. Set your timing right, thats probably gonna affect your emissions also.
3. If you really do have an HC problem (which would mean your car is obviously misfiring UNLESS accompanied by some CO) check ignition things.
4. What kind of gas you using.