Hey, glad you got it sorted. I'm having a similar issue with my 2013 i3 rex and was wondering if you could elaborate any more on the faulty spark plug causing a sensor error - namely was there any fault codes prior to replacing the spark plugs and also do you know what sensor was causing the...
I'm having the exact same issue with mine - originally the range extender would work intermittently, sometimes I would get 50miles and then have to leave it for 15 minutes or so, and then maybe get another 5-10 miles out of it. After a while it would be more like 5-10miles and then for a while...