I received an Innovate Wideband lambda/oxygen/AFR gauge for Christmas and decided to get it installed on my ’87 classic Mini today. Last year I fitted a new stainless exhaust system with a stainless Maniflow LCB 3-2-1 exhaust header, stainless centre silencer and RC40 millennium twin centre exit DTM back box. The lambda sensor requires fitting a threaded boss into the exhaust. The exaust system has a Y piece where the headers join to the centre pipe, and this is th most appropriate place for a lambda sensor as it measures all cylinders.
I don’t have a car ramp, or TIG welder, so decided to phone around to see if there was anywhere locally that could do it. I called STS Tyres in Redhill who said they could, and took a drive down there. 30 mins and £30 later I had a boss and sensor installed. I tied up the loose cable and headed home. At this point I noticed the alternator light had come on so I thought I’d better get home quickly. I then realised that I had read the sensor should always be connected and powered while the engine is running or it will be damaged. So I pulled over and made a very temporary, bodged and dirty install of the gauge by pulling the dash apart to find a live and earth. I should at this stage have calibrated the sensor in free air rather than still installed in the exhaust.
At least this meant I could test the sensor on the way home. It looks like the car runs around 14AFR while cruising, and down to around 10 under heavy acceleration. I think this isn’t too bad considering I had been turning by spark plug colour and thought it had been running a little rich anyway. I will lean it out slightly, but think perhaps the needle is a little aggressive with adding fuel under acceleration.