Misfire under load

Morning and welcome.

any idea why two of the new plugs are so corroded around the base? for them to corode like this means water/coolant/fluid is getting on them, possibly running down the coil pack - fluid will flow to the lowest point and the whole of the base is corroded. two of the coil packs are also showing signs of water damage. water and coil packs do not mix.

Might be plug or coil pack playing up but i would find and sort the source of the leak first as this is the likely cause of your problem.

isn't P0300 the boost control valve (dump valve)

cant make out whether you have 2 makes of plugs or they are iraduims can you confirm this ?

, when you changed did you replace all 4, that's an awful lot of corrosion if they only fitted in January, which may indicate that you have dampness in the dic causing a miss fire

Kez, if you enlarge the pics the plugs are all the right type, the 'gap' on plug 2 looks massive! also if you enlarge the coil pack pic you can see the water ingress on two of the coils - my money is on water/fluid getting in.

actually i got this for p0300 - http://www.permoveo.ltd.uk/tabid/122/OBD-Error-Code/P0300/Diagnostics/Saab/Default.aspx

the 1st 2 plugs to be that rusty mean water has been getting into the chamber,how is another mystery..
p0300 is random misfire code