Removing EGR can cause a loss of fuel economy. Why? Because EGR gases that are reintroduced into the engine help to fill the combustion chambers, which slightly reduces the amount of fuel needed. This only happens at part throttle cruise, and if the EGR system is operating properly, it should never cause a problem with WOT or idle.

I know EGR removal causes loss of MPG because of experience. My old SVO...I cut off the EGR completely and plugged the manifold. MPG dropped from 27 to 22 with no other changes. That is one reason I left EGR on my Merkur....MPG is good and that is the #1 reason I bought the POS.

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record breaking '75 Maverick bracket car 2 time track champion, '84 Mustang LX bracket car, '78 Fairmont Futura, '86 Merkur XR4Ti, '95 F250 PSD, 00 F150, '03 SVT Lightning (DSG) #888