Related Photo Galleries
18 The final piece to install is a wide-band oxygen sensor, which provides the engine controller with specific feedback on the oxygen content of the exhaust gas (rather than the simple lean-or-rich feedback of a narrow-band sensor). This enables the controller to adjust fuel and—on the MegaSquirt II and other controllers—ignition timing more precisely. (The basic MegaSquirt used here doesn’t allow for easy timing adjustment.) The sensor is mounted in the exhaust system, where the Y-pipe merges with the single outlet pipe.