My Cousin's got a 09 BMW Z4 with a P0303 code. Swapped the Coil to another cylinder, same code, Changed the spark plug, same code. Reset the ECU each time, same code. What do we do next?
On an interesting side note, the Spark Plugs are Bosch Copper Nickle three prong plugs that needs a 14mm/12 point socket. First time I ran into that.
71k mile on the odometer.
Yes, Bosch spark plugs for BMW use that multi-ground electrode design (OEM). I don't use those plugs for my BMW. I use NGK laser iridium plugs for mine as they are one-step colder compared to those Bosch plugs (absorb more heat from the cylinder; spark plugs have a double-duty).
I would do a compression test on that cylinder to see whether it's an engine problem or an electrical problem, or even a fuel injector problem.
