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What is a Finger Stick? It is a simple circuit that modifies the MAF signal on LLY engines (not LB7 engines) to expected levels when the EGR is blocked or a free flowing exhaust system causes the ECM to set codes. This will prevent a Service Engine Soon light from illuminating and will prevent the ECM from displaying DTC codes related to an EGR modification or larger exhaust.

There are other threads on this forum that cover the theory in much greater detail. Consider this the short version.

How to order:

Click HERE to order a Finger Stick via PayPal . This is the only method of payment accepted by me for small orders (credit card payments may be used via the Paypal website without creating a PayPal account). The E-mail address you enter on the PayPal site must be valid. Confirmation E-mails will be sent to you in reference to your order. If the E-mail is not valid, the payment for your order will be returned to your Paypal account method of payment and the order will not be filled.

www.kennedydiesel.com has started to distribute the Finger Stick also. The Stick is part of a blocker package put together by Kennedy. Go to the web site for pricing and ordering.

Ask you local shop. There a several shops across the country that have been stocking the Finger Stick. I do give discounts to anyone that buys 10 or more at a time.

What follows are the connection instructions for the Fingers stick:

Everyone must be reminded that I am providing this "as a generic circuit" and that you install it at your own risk. I can not, and will not, be responsible for any damages, real or perceived, to you, your truck, or your marital life in whole or in part. Same goes for these installation directions. Read all these directions before installing. Ask questions first, install second. There will be no installation instructions included with the Stick.

And before you ask; No, I have no plans to add connectors to the Finger Stick for easy installation. :)

You will only need to cut one wire! All others connections are simple tappings into the harness wires.

Each wire's function is based on it's location on a connector. Make sure you follow the wires back from the MAF and EGR connectors. You never know when GM will change wire colors.

This is a picture of the Stick as shipped with each wire labeled as it will be used in the installation.



This picture is of the EGR connector. The lowest passenger side wire on the connector is the EGR position sensor wire. On the example truck it is blue with a white stripe. The BLUE wire on the Stick should be tapped into this wire. It is not necessary to cut the original EGR wire!



This picture is of the MAF sensor near the air filter.



The wire closest to the driver's side is the MAF signal wire. On the example truck it is yellow. This is the ONLY wire that needs to be cut. Splice the YELLOW wire on the Stick to the MAF sensor side of the cut wire and the YELLOW/GREEN to the harness side.

The next wire in is a ground and is gray on the example truck. The GRAY wire from the Stick gets tapped into this wire, You do not need to cut this wire!

The middle wire is the power wire and on the example truck it is pink. The RED wire on the Stick gets tapped into this wire. You do not need to cut this wire either!

Installation Notes:

The EGR MUST be plugged in for the stick to operate properly.

It is much easier if you disconnect the air intake filter tube from the filter before you start. This will give you more room to work.

Wait until after you install your Stick, then clear all EGR DTC codes that may have been set, if desired, or 50 ignition cycles will eventually clear them.

Once the yellow wire in the engine harness is cut, the YELLOW wire of the stick will go towards the MAF wire on the air cleaner, letting the output of the stick (YELLOW/GREEN) go into the harness that goes across the engine.

For the wire connections. you can use wire taps, sometimes called splices or Scotch Locks. There are available at the local auto parts store. The wires on the harness and stick are thin, 22 gauge wires so make sure you get taps that handle the small wire. However, soldering is even better and is the recommended method of connecting the wires.

For a clean install: Pull the plastic wire looms back far enough to make all the wire connections and splices easier, and don't put any wires back inside the looms until all the connections are finished. Then, when you're completely done, tuck everything back inside and finish with a little electrical tape to make the ends sanitary. For even a cleaner install, after plugging the EGR back in, you can put a piece of 1" wire loom from the MAF sensor down a foot to where the wires “T” in.

Other Notes of Interest: For dealer / warranty work the stick may be left on the truck, but like all after market things, out of sight out of mind. You may want to remove the Blocker Plate (remember, out of sight, out of mind). The ECM should stay happy with the Stick installed and the Blocker Plate removed. You may have to leave the stick on to keep the big exhausts from setting codes. To the manufacturers’ knowledge, it is invisible to the Tech II diagnostic computer. The EGR works the same with or without the stick. What is modified is the signal coming from the MAF sensor. So, disconnecting the Blue EGR wire stops the MAF signal modification.

If you are coding because of the exhaust, disabling the Stick will bring the codes back.

How to disable the Stick if needed: If you disconnect the EGR wire on the stick (the blue wire), the Stick just passes the MAF signal to the ECM without modification. If you are blocking codes, the codes will come back with the EGR wire disconnected.

Is there a way to tell if it’s working (without using a DTC scanner)?

Remember, if the EGR Blocker Plate is installed along with the Stick and you are not getting any DTC codes, it is working. Disconnecting the blue (EGR) wire as stated above will disable the Stick and cause DTC codes to be displayed again. If you installed the EGR Blocker Plate which caused the SES light to go on (CA & N/E Emission trucks mostly) – the SES light will be off if all is working fine. If you installed the Blocker Plate and never got a SES light (mostly Federal emission trucks) then you could also try this:

If you have a volt meter, you can look at the voltage coming out of the EGR position sensor relative to ground. That signal is in the blue wire you tapped coming from the EGR. If the voltage reading is greater than ~1.25 volts at idle, the EGR is being used and there are no EGR codes. If you watch the voltage while you rev the engine, it will fluctuate. Any EGR codes and the ECM will discontinue adjusting EGR positioning. A closed EGR valve reads about 1.25 volts. Full open is near 5 volts. Normal idle is about 3 volts.
 
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