Hi all car failed today, the co was 0.49 should be 0.30ish fast idle only, tick over idle was ok, dude that did it said everything else was spot on could be sucking in air from the exhaust some where, also said try run some redex through it and replace the exhause gasket, as the one I got was just a flat plate not a crush type

I had a thought when I started the car up after the HG I had some hoses the wrong way round and it was idling at 1500rpm could the ecu have self learnt to this and is now over fueling, how do you preform an ecu reset

battery off for half hour or so then battery back on. it should reset just let it idle and take it for a drive through the gears and rev range. redex i would say is the first course