P0300, P0302, P0304, P0306, Engine running rough with little power

[X5Cat]

Thanks, jfoj. I do realize vacuum leaks will [I]cause[I] misfires. What I am curious about though is how that plays out with the DTC's. If a vacuum leak causes a cylinder to misfire (or, let's say rather to fail to ignite), but the plug is firing normally, do you still get a code that there is a misfire? And would I not get a code for a vacuum leak?

[jfoj]

I have been doing this a long time and the standard P300 and P30X codes do not differentiate between ignition and Lean problem.

But you are RARELY going to have a multiple misfire situation due to coils or spark plugs. Think about it, car ran fine a few days ago, then BOOM, multiple misfires on more than one cylinder and a general misfire code. You do not have multiple coils or spark plugs fail at the same time.

Freeze Frame info helps a lot to figure out what is going on. Coils and plugs have problems under high cylinder pressure conditions, under heavy throttle, not idle or cold start.