What is a EGR Delete? Why should I delete this on a Duramax

uramax Life Decals 👇Thanks https://www.ebay.com/itm/283221137628 $10.00 Sponsor: Werhrli Custom Fab /coupon code: Truckmaster for free shipping Instagram @truck_master07 New T-shirts and hoodies! https://teespring.com/shop/truck-mast... Send me cool stuff! Mail time ever month! Truck Master P.O. Box 525 Perry, MI 48872 Channels to check out: Rustbelt Mechanic (bed lined paint job)    / @rustbeltmechanic   JW Montoya    / @jwmontoya   Bertrand850    / bigstallion80   Duramax_diesel    / @resurrecteddp   Mods done to the Truck! EFI Live DSP5 Switch Idaho Rob WCFAB Stage 2 Air Intake Kit WCFAB Hotside intercooler tube Billet Turbo Wheel upgrade WCFAB YBridge FASS Titanium 150GPH Lift Pump FASS Fuel Sump Kit MBRP 3inch Turbo Down pipe Cat/muffler delete PPE Race fuel valve Ported fuel fitting Transgo Jr Shift Kit Resonator Delete Egr Delete Egr Cooler delete Sinister Cat Fuel Adapter Sinister 4 inch Exhaust with AR15 Tip PVC Reroute PPE Stage 5 Built Transmission Zone off-road upper control arms PPE Stage 3 HD Tie Rods 6" Pro-comp suspension lift kit 5100 Bilstien Shocks 35/12.50/R20's 20x12 Vision Prowlers -51 offset Trail Ready Front Bumper Music by: suncloud