how to plug hole on the header were egr is?
If you need to plug rear O2 holes, there is a certain size oil drain plug that will take care of that. Can't remember the size though, been a while since I did that. Maybe someone else can provide that info.
I'm guessing it's the EGR hole that you need to fill though. It would be on the passenger side header. Rear O2s are not mounted on the header, and cats or not you need the front O2 sensors so you shouldn't be filling those holes with anything but the O2 sensor.
Mike






