whats it do, is it worth doing and how do you do it

EGR - Exhaust Gas Recirculation valve. Does what it sounds like !!! The only reason to bypass it is the valve can leak when they get old and this causes a vacuum leak in the intake ! Don't think it can be done with the engine in situ but do a search or look on the tech sites !

It can be removed by removing the gearbox for access, i removed mine this way and it was a pig of a job. You could disconnect the EGR solenoid in the top left of the engine bay, blank off the vaccum pipe to the EGR valve and remove the redundant vaccum pipework, this obviously leaves the valve itself and the pipework to the inlet manifold in place to be removed at a later date when the engine is being worked on.

 

Baz