I've had a warning light on which once checked out has pointed toward a faulty O2 sensor. On further checks the Lamda's and Cats are fine and all working perfectly. The car has shown up a slight misfire on 3 cylinders 1, 3 and 4 which the garage suspects might be the root of the problem.
I just wanted to ask if anyone had any issues similair to this in the past? I have yet to take the plugs out and visually inspect them. Just bought the car a month ago. It performs well and I have no signs of problems other than the light being on.

Cheers.