Does anyone have suggestions for sniffing a Kess KWP protocol flash on CAN high/low wires?

Normally, I plug a k+dcan cable into a Y splitter cable and listen live with putty or some other serial logger.

However with the Kess, when I plug my K+dcan cable in the OBD Y splitter, there is packet loss whether i'm listening live or not. It shows as either unable to identify ECU or or it identifies it with bad data ie VIN and HW ID appear truncated. The sniffed data is accurate up until the failure too.

I have both a genuine and non kess both of which behave the same in this scenario.

I am open to hardware suggestions as well.

It is a ft232RL and could not find anything relating to muting in the datasheet.

Take a look for another cable with SOIC8 inside. If it´s MPC2551 inside replace it with a TJA1050, then you can mute it by connection.

Thanks this worked to a point where the communication with KESS is not disrupted. However, it seems i'm only sniffing maybe 5% of the traffic (but are clean packets logged)

Or simply use another kind of logging devices... such as Salae or Kingst Logic analyzer to log "start communication" - and your tool enabled with delay to grab another data ;-)