That would be p0301, and that code is only a missfire indicator, doesnt indicate whether its rich or lean just that there is a miss or has been a miss in that cylinder. If its an igniton related miss the cylinder would be rich due to fuel not being burnt but if its an injector or manifold gasket leak the cylinder will be lean due to either no/minimal fuel injection, or excessive/unmetered air intake into the cylinder. Just by plugging ids in theres no way they can tell