I really wanted the A/F ratio meter on the dash of my ‘68 Camaro for my next SCCA Solo II outing, so I decided to buy the third generation WBO2 and controller from Holley. Since my first generation controller had the more desirable NTK controller but didn’t work with the only gauge commercially available and nobody on the message board at www.chevytalk.org had a wiring diagram to attempt a hack, I was torn between ponying up $600 for a new third generation NTK sensor (PN 534-188) or the $300 for the Bosch sensor (PN 534-197). The main difference seemed to be the NTKs ability to withstand leaded gas a little better (although it’s not recommended for either sensor) and because I wasn’t intending to run any leaded gas I decided to go with the Bosch. I picked it up from the Car Shop Inc, who again had the best prices I could find. I pulled the NTK sensor out of the O2 sensor bung I had put in the exhaust system but this time ran the wires for the Bosch sensor up through the shifter boot and into the console, where I decided to mount the Holley Commander 950. I had room in the center console in front of the shifter lever for the Commander 950 ECU and the WBO2 controller box, both of which I mounted with industrial Velcro. Now the Holley in-dash A/F gauge (PN 534-200) was a simple plug and play affair, after I sourced the PDF document from the Holley help desk. Unfortunately no amount of searching their web site or inquiring on the forums was able to turn it up, but after a few emails to Holley they sent it to me electronically. I snipped a little piece of sheet metal and fit it in a hole in my dash and drilled a hole in it to mount my gauge. In addition to the plug to the controller, it needs switched 12 V and ground. It has an optional connection for dimming at night time which I didn’t worry about for now. Now I could see my A/F ratio right on the dash in real time. Cool! I cable tied everything down and got all of my tools out of the car, because it was time to autocross again!