No use for adjustments.
Only information.

 EGR Error -- Calculated error as percent of actual commanded EGR. Negative percent is less than commanded and positive is more than commanded. The greater the value, the more likely the EGR valve is sticking.

See here for more parameter:

http://www.totalcardiagnostics.com/support/Knowledgebase/Article/View/43/6/reading-performance-information-data-pid