Virtual Mechanic

PURPOSE
The EGR valve is design to recirculate exhaust gases but only after idle and before full throttle.  The EGR valve operates mainly on cruising. 

THINGS TO LOOK FOR
Over time the EGR valve may be responsible for poor idle.  EGR valves are sometimes difficult to pinpoint as being the perpetrator of a poor idle.  A quick inspection to see if the needle is moving or if any exhaust gases are coming from the valve may be determined by an electronic fuel injection specialist.
 
IS IT EXPENSIVE TO REPAIR?
The EGR valve can be expensive.  You can try the wreckers but nine times out of ten a new EGR valve is the best way to go as the second hand EGR valve would usually have been on the engine from when the vehicle was new.

TEMPORARY REPAIR AND LONG TERM REPLACEMENT
Most EGR valves are not serviceable.  The EGR valve is specifically designed to eliminate or reduce exhaust gasses entering the atmosphere.  Tampering with an EGR valve may incur fines.

This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009