This is Keebler65’s old guide. Some of the chipset and software info is a bit dated, but the techniques are good.

ECU Chipping

You need to add a few additional components to the original Honda ECU. It requires some soldering skills and should not be attempted unless you have soldered before. (Chances are you know someone with soldering skills that could help you). Here is a picture of the P28 ECU that I chipped, before any of the parts were put in:

Before you can solder the parts in, you will need to de-solder the holes in the circuit board since they come filled with solder from the factory. You can buy a “solder sucker” to do the job, however unless you get a nice one (expensive) they don’t really work well in my opinion. The cheap and easy solution is to buy some solder braid. It’s just braided copper. Simply place it over the hole to be de-soldered, and place the soldering iron on top of the braid. It will then wick up the solder into the braid. It’s available at radioshack:

You’ll want to use a decent quality soldering iron to get the job done nicely. The important thing is to not use too much heat, and also make sure the iron has a fine tip on it. I’m using a standard Weller iron:

Here is what it should look like after the board has been de-soldered:

The parts that need to be added are boxed in with a dashed white line. The parts consist of (2) .1uF ceramic capacitors, (1) 1k resistor, (1) wire jumper (simply a piece of wire…I used a lead of the resistor), (1) 74HC373 chip, and (1) 29C256 chip (thats the EPROM). The resistor and capacitors have no polarity, so you don’t have to worry about installing them backwards. The 74HC373 chip does have a polarity. Pin 1 will be on the left side of the pic (you’ll see in detail later one). The same is true for the EPROM chip. Since it would be impossible to burn a chip and have the tune be perfect, it becomes obvious that you don’t want to solder the chip in. Instead, use a socket so that it can be removed. You have two options: for less than $1, you can get a standard DIP socket. The problem is these are very hard to insert and remove the chips since there are 28 pins (it requires a lot of force and is hard to grip the chip). Your second option would be a ZIF (Zero Insertion Force) socket, which costs less than $10. It is a socket that has a lever: pull up the lever, set the chip in/lift it out, and flip the lever back – VERY nice to have since you’ll be doing this many times while tuning. Be careful when ordering the ZIF socket, as many of them are too large to fit on the board without running into things. The first ZIF I bought was made by Aries, and it was a very quality piece, however, it was too large and bulky to fit without a lot of modification to other components on the board. I ended up ordering a different one that was much more compact. I am unaware of the brand, however it is blue and is referred to as a low-profile ZIF. The only problem was that the lever end of it was in the way of the 74HC373. The easy solution is to buy a standard DIP socket as mentioned above. Solder this onto the board. Then, stack the ZIF onto this socket, which raises the ZIF away from the board enough to clear the surrounding parts. This setup worked very well for me. The following picture shows the too-big-to-fit ZIF in the back-left, the low-profile ZIF in the front left, and the DIP socket on the right:

The ZIF socket stacked on the DIP socket for added height:

And finally, a couple of pics with all of the parts installed:

I ordered most of my parts from www.jdr.com except for the low-profile ZIF socket and DIP socket, which I obtained from www.jameco.com. The following table containse the exact part numbers that I ordered. You’ll notice that I ordered two EPROMS. This way, it will be easier to burn one while the other is installed.

Additionally, I have recently located all of the parts you will need from one source. DigiKey is where you can find them. Their inventory selection can be overwhelming, so here are the part numbers you will want:

And for a final update to this page, I’d like to add that you can find ALL of the necessary chipping parts at moates.net. It is a great deal in my opinion, and you’re guaranteed to get the correct parts the first time around. It’s under the name of “Honda ECU Chipping Kit”.