[dumdum]

Also lightned crank pulley or lightned flywheel can cause phantom missfires on all 4 cyclinders.With custom tuning you can go back and change the parameters the ECU uses to decide when to trigger a CEL.Its set at the factory for" 1 missfire" triggers a CEL.I have adjusted mine to "3 missfires" triggers a CEL as my ACT Streetlight flywheel will sometimes trigger numorous random missfires every now and then.Sometimes days apart,sometimes months apart.