I recently purchased a cheap OBDII reader to diagnose a fault on my brother's Jag (failed lambda sensor). It will also read/reset fault codes (and show other live info such as throttle position, ignition advance, temperatures etc. depending what your ECU divulges) on lots of modern bikes. If you've got a yellow engine management light somewhere on the instrument cluster then chances are there's an OBDII port somewhere.
I was also having some issues with my Sprint. Since I bought it there was a slight, intermittent misfire on idle but not bad enough to worry about. Recently though it started surging under acceleration, to the point that riding at low speed round roundabouts it probably looked like I had no idea what a clutch is for.
My initial diagnosis of an air intake leak turned out to be correct (first time for everything), knackered "intake trumpet" which connects the air box to the throttle bodies.
Since I had already dismantled various bits to verify the diagnosis I figured it was an opportune time to check the throttle body balance. Some research led me to conclude that I needed more advanced tools to balance the throttle bodies so I went mad and splashed twenty quid on a cable that lets me use TuneECU to read additional info needed for the balance.
I'm happy to report that replacing the trumpet fixed the surging issue and the misfire, and the throttle bodies were nicely in balance.
TLDR; I now have an OBDII reader, and also a cable that allows TuneECU to work with a lot of fuel injection Triumph bikes. If anyone would like to borrow either of these for diagnostics etc. then just send me a message
