What plugs did you put in this truck,this has the Nissan K21/K25 engine and they dont run well with aftermarket plugs in them,is BEST to use OEM plugs in this truck. As for the coils,you can unhook them so that only one coil is firing and if the engine stays running at a lopey idle then that coil is good,check all four coils individually,any that wont keep the engine running i would replace,might be safer to just replace all four of them anyways if the plugs were worn,how many hours are on the truck??