Hi all. My car has been so reliable that I haven't been here for a year and a half. Now at 218,300 miles it has a misfire. 96 OBW EJ22 5spd.

 

Yeah yeah I know change the plugs and wires. But would bad plugs and wires cause this:

 

It only misfires below 3000 rpm. It bucks severely from idle to 3000, then instantly smooths out and pulls strong every time.

 

It did that for a month with no cel. Then the cel came on: code for #4 mis.

 

What could it be?

 

if the coil pack is dirty will arc to the holdown bolts on coil [once it makes a track it will always follow the path of least resistance] take off the coilpack clean it and check for tracks from posts on it look like white or grey lines inside coil boots

If that doesn't work out look for vacuum leaks( probably a big one).

check the timing?

how old is the belt, idlers and water pump?

Simple stuff first, plugs, wires, check vacuum and PCV hoses.

How long has it been since the timing belt was serviced?

T-belt, idlers, and water pump were replaced 2 years, 14000 miles ago. Tensioner seemed ok, so it wasn't replaced.