Engine management light is on the dash and vehicle has a misfire. A full serial scan was carried out using OE Vauxhall software. Various fault codes were found regarding engine cylinder misfire.
Vehicle was road tested and live data monitored. Further testing was carried out in the workshop. A faulty EVAP solenoid was found and replaced with one in stock. Ignition coil (multi COP) unit was found to be non OE and replaced with one in stock. Vehicle was allowed to idle, reach operating temperature and various data was monitored. We found the control module was shutting down fuel to two cylinders. Further testing revealed a faulty engine control unit (ECU).
I believe the fault had occurred due to water travelling through the EVAP system and damaging the engine control unit, hence the rusty EVAP solenoid. Large amounts of water was found in the EVAP canister.