In the January 2012 edition we described the interface board for a wideband lambda probe. This versatile board can be used in stand-alone mode or more conveniently from the comfort of a PC or laptop using its serial interface port. When used together with a computer the interface has access to the diagnostic features of the CJ125 lambda probe interface chip and allows measured values and operating conditions to be stored for analysis later on. The interface board is set-up and controlled using a simple set of commands.