How did you manage to get authorization for them to replace the piston rings? Was it a compression test that failed or was it oil consumption. Just getting my catalytic converter replaced now. Misfiring was only occuring with all new bits and new software when the emissions light came on and stayed on. Hopfully thatl be it now unless i have ware to my rings. Time will tell though
Oil consumption. They kept my car for 3 days to do some tests.
Maybe I'll call them and ask for spark plugs to be fitted.