How to buy/install the MAF


Miller provided an eCommerce code that gets you the right kit at our discounted cost of $300. PM me and I’ll give it to you. It’s for SpecE30 racers only.

What you get. MAF and a chip. The chip is, of course, not tunable. No longer are you the only person w/o a cheater chip. Yes, that was a joke. It’s the standard Miller WAR chip, as I understand it, except modified to use the OEM red line.

Installing the chip. Pull out your DME and straighten the clips that hold it’s cover on. The chip you want to remove is in a “socket” that allows it to be removed with some careful work prying it up. The pic below, of an aftermarket TRM chip, shows you the location of the chip. Look closely at the chip and note the notch at one end. Your Miller chip has that same notch. That’s how you tell the proper orientation of the chip.

This is a bad time for static electricity. So if there’s any chance you’ve got some static build up due to clothes or carpets, lick a finger and touch a metal modern appliance that is plugged in.

Get a little screwdriver in between OEM chip and socket and pry the chip out of the socket. Note that often you will find that the chip has a little plastic retaining device too, and getting that off is a matter of prying also.

Once your cheater OEM chip is removed, do a test fit of your Miller chip. Carefully observe the width of the chip’s pins vs. the little holes that they have to go in. It is common to have to give a chip’s pins a little squeeze. What you have to carefully avoid is attempting to press the chip into place with pins that are not aligned into holes. That will bend pins and make life harder for you.


Wiring for the MAF. Pull the rubber boot off of the AFM cable connector so you can see the 4 wires. The wire colors can be hard to make out because they are so old. Work at it tho because, well, you need to cut the right one . Here under the boot is not a great place to cut a wire, but it is the best place to see the wire colors.

From top
Blue with Gray stripe
Gray with White stripe
Gray with Yellow stripe
Gray with Violet stripe

You need to cut the Gray with White stripe wire. The Miller instructions say to do it near the DME, but for your test car, it will likely be more convenient to do it near the AFM. My harness had a convenient spot about 10" prior to the AFM connector to cut it. I had to examine the wires pretty carefully to make sure I was cutting the right one.

Cut the Gray w/ White wire and put a pair of connectors on it. That will allow you to easily convert from “AFM as usual” to “MAF Test Car”. If you put the female connector on the wire that goes to the AFM, than make the 12V wire (next paragraph) male-male.

Make a jumper wire that will go to Key On 12V. I pulled Fuse 8 (rear window defogger) and stuck a connector in. Run that wire to the MAF via the connector you put on Gray w/ white. Don’t send that 12V to the DME by connecting 12V to the wrong end of the wire you cut. What’ you’re doing here is giving the MAF it’s 12V supply V.

Plug your vac ports. The rubber elbow is a source of vac (1 of 3) for the brake booster. The port on the elbow and on the hose near the elbow will need to be plugged. Some tape will do. Elsewhere there is a post about simplifying your brake vac set up.

The rubber elbow. You have to stretch it a bit in order to get it to fit on the MAF. This wasn’t easy. Using a pan of hot water, per Miller’s suggestion, didn’t work all that well for me. What ended up working is I used some grease and screw drivers to force the elbow on to a can, and let it sit for a couple days. That seemed to stretch the rubber a bit. Then I heated it up again, used some grease and some non-metallic little pry-bar type things, and got the elbow on the MAF.

Buying a new rubber elbow. Because old rubber is less pliable, Miller suggests buying a new rubber elbow. But there’s several different kinds of E30 elbows, the most important difference is that it synchs with your type of Idle air Control Valve (ICV). The elbow in the pic uses a T shaped ICV. Many ICV’s are “L shaped”, not T shaped.

Use some zip ties to fasten your air filter to the old air box bracket.

Use some imagination to get the air filter to seal well on the MAF tube. Mine was kinda loose.

Boiling rubber elbow to soften it.

Stretching rubber elbow for a couple days with a dogfood can.