EGR DELETE — 20-23 DURAMAX 6.6L L5P

If you are running emissions-off tuning but leaving the EGR in place, unplug the connectors circled on the passenger side of the engine so the truck throws no warning codes. Then stop here; the rest of this guide removes it.

Find the packing list in the kit and double check you have every item on it.

Remove the plastic threaded plug at the passenger side lower corner of the radiator. Leave the coolant tank cap on: it is reverse thread, and with it off the coolant blasts out of the drain all over the front suspension. With the cap on it drains slowly into the bucket with much less mess.

If the disassembly is giving you trouble at this point without the pictures, we strongly recommend you do not continue and take the truck to a certified diesel performance shop for the install.

First remove the heat shield on the pipe that connects the EGR valve to the cooler and to the Y-bridge, then remove the six 13mm bolts holding the pipe on.

The PCV hose has a non-removable metal band. Loosen and spin the clamp with a hook tool or flat blade screwdriver first, then with pulling force and a flat blade or pry bar pushing on the bottom of the hose, it will come off the horn with the band staying in place. Leave the PCV hose connected to the PCV box on the driver side upper valve cover.

Two bolts. You need a 13mm swivel socket on a 1/4" drive with a long extension. If you drop them, no big deal: they will be easy to reach soon.

Leave all the connecting hoses in place. Remove only the aluminium hardline assembly for now.

It is a spring clip on the plastic cold-side pipe at the cast aluminium Y-bridge / throttle blade connection. Once off, cover the intercooler pipe with a plastic bag or shop rag so nothing falls in for the rest of the job.

There are several Christmas tree clips along the harness and several smaller connectors. Release every one associated with the harness on top of the bridge so the bridge can come out. Disconnect the connectors on the throttle blade too.

The A/C compressor has to come loose before the Y-bridge can come out. With a 1/2" ratchet on the belt tensioner, release the tension and slip the belt off the upper pulleys. You do not need to remove the belt completely.

The bracket sits on top of the A/C compressor; set it aside. Remove the alternator as well and set it aside.

Four 15mm bolts. Slide the compressor forward toward the fan shroud for better access to the Y-bridge bolts.

With a 1/4" drive 10mm socket and a long extension, remove all eight bolts, four on each runner. The bridge comes forward slightly, then up and out. The bolts stay in the bridge in their OEM rubber inserts, but be very careful of anything falling while the bridge comes out, because both intake runners are open. Once it is out, stuff rags into the runner ports. Set the bridge aside for reinstall.

It connects the lower EGR valve to the upper. Remove its heat shield, then the four 13mm bolts, and take the pipe off.

Disconnect all the coolant hoses at the upper EGR valve, then remove the four 13mm bolts and nuts holding the lower valve to the exhaust manifold and lift it off. Use a lubricant on these bolts: they break off easily. Tie back the lower valve's plugs.

With the new gasket and hardware, reusing two of the original studs and nuts. Torque to 25 ft-lb.

They run from the thermostat crossover housing. One large spring clamp next to the turbo (leave the clamp on the hose, it is reused), four 10mm bolts and one 13mm bolt, all circled in the photo.

From the EGR fix kit parts bag. Grease the O-ring, then fit the plug into the coolant port on the thermostat housing just in front of the passenger side intake port. Fasten it with the OEM bolt removed in the previous step.

Five 13mm bolts hold it to the engine. Remove them and lift the cooler assembly out.

It connects the firewall heater core hose to the lower radiator hose. At the heater core end, push in the blue plastic tab to release the connection from the firewall, then push the small clip back down into place. At the bottom, just in front of the upper control arm, pull the hose off the hardline and leave the spring clamp on the hose for reuse. Remove the bolt holding the hardline to the engine.

The brass barb end goes into the OEM hose at the bottom with the OEM spring clamp, as shown.

It clips onto the fitting on the firewall just like the OEM hardline did. Push until it clicks into place.

The injector sits in the front elbow of the exhaust just below the down pipe. Pull off its small rubber hoses and cap the ports on the fuel cooler line with the supplied HPS caps and clamps. Unplug the DEF injector and tie it back out of the way.

That is the EGR side done. If you are fitting the 3 1/2" down pipe, do that now; otherwise go straight to reassembly.