A: Without the FS, people will typically see P0401 and P0404 codes when installing after market exhausts or blocking the EGR. These are the codes related to the sensed EGR flow is not being within expected values. The Finger Stick does not actually block any codes. Instead, it modifies the signal from the MAF sensor based on the EGR valve's position. This provides the ECM with the values it expects for intake air flow. Therefore, the Finger Stick is a signal modifier, not a code blocker, and requires an operational EGR
valve to work properly.

A: No. It has been our experience that the EGR motor does not give the proper signals unless installed in the housing with the valve attached. Kennedy Custom ECM programming is the solution for deleted trucks.

A: Due to the low voltage nature of the system soldering is required

A: Wires should always be traced back to their connector. The wire's position in the connector determines its function, not the color! GM has a bad habit of using the same color several times in the same harness and even changing the color. It is up to the installer to take the time to verify where the wires go.

A: Only the wire for the MAF signal needs to be cut and separated so that the signal can enter the Stick, be modified, and continue on to the ECM. All others are simple taps into the wire.

A: The bottom of the plate frequently catches on the bottom of the main hole through the flanges and gasket. Filing a little taper on the bottom edge of the plate helps. It is not catching on the studs.

A: You have a leak. If re-tightening the flange does not stop it, you might have damaged the gasket. Remove the plate and coat it with “Form a Gasket Copper”. Let that set and re-install.

A: Yes, but you will set codes and the SES light will illuminate.

A: Yes, though not recommended. The plate stops the flow of soot back into the engine.

A: Very first thing is to check your installation. Ask a buddy to check for you. A fresh set of eyes frequently pick up on a problem that you have been staring at for hours. If that doesn’t work, get the codes read. When you read the codes, write down the EXACT number as this means more to use than the description.

There have been recent (early 2007 calendar year) software updates from GM to correct for numerous DTC’s that occur in completely stock 2006/7 LBZ and LLY trucks. It is recommended that these updates be applied before any further troubleshooting is done. The Q and A below assumes that you have already done this.

A: You didn’t install the blocker plate did you?

A. This indicated a problem with the installation or the stick. In short, it isn’t working at all.

A. The problem is the Stick is not modifying the signal from the MAF sensor. The most common reason is the customer is into the wrong wire(s) in the harness. You must trace the wires back to their connectors to be sure you are into the correct wire as outlined in the instructions. The next most common problem is the customer has not cut into the MAF signal wire, only tapped into it.

A: It is likely that you have an aftermarket air intake. Try switching back to the OE intake. This will likely cure it. Also some LBZ trucks are just “off” and set this code for no rhyme or reason.

A: P0405 is as close to a general failure as you can get. Basically, no signal is getting through the Finger Stick to the yellow wire in the harness. The cause is almost always an installation error.

The Stick may not be getting power. (Red and Gray Stick wires not hooked up to the right places).

The Yellow wire from the MAF is not making a good connection going into the Stick. The Yellow/Green wire coming out of the Stick is not making a good connection going into the engine harness. Instead of tapping into the MAF wires (gray and pink) you cut them which disables the MAF sensor.

The most frequent cause is the installer did not trace the wires back to the connectors on the MAF and EGR as instructed. Instead they used the wire color which is WRONG! GM reuses the same wire colors for several function and circuits.

A: The EGR valve itself is having problems. Remove the stick and plate. You will be going to the dealer to get it repaired. The Stick needs to have a functioning EGR valve to do its work.

 

For more information about the function of the Duramax EGR system please reference this page:
https://kennedydiesel.com/tech-tips/duramax-tech-tips/duramax-egr-blocker-vs-egr-disable-vs-egr-delete/