out for fellow members here in SoCal. Installing an egr system after the motor is in the car is a major undertaking (if possible). We're also likely talking about cars that are getting on with mileage (not newly built motors)....and might be on the edge of the limits. The egr definitely affects the HC and CO levels.....not just the NOx. So when the egr is disconnected (non-functioning), it pushes up the other numbers.
Since this mod is not easily reversed, I am questioning this mod for a California car that does not have a smog test "hook-up"..
