Yes, sorry, "Cat Efficiency Below Threshold". Back in 2009, the workshop first decided to replace 2 lambdas. The error came back, then they changed the other two. Obviously they did not perform a proper catalyst fault diagnosis. The error has been coming back on and off for three years according to the papers I have, but lately is mostly on. I've had the car for 1 year only.
There is only one record of misfire, and that was last year before I bought the car. 1 coil was replaced. I noticed however that one coil had also been replaced in 2006. So now one coil is from 2012 and 3 are from 2013. There is no service history suggesting any misfire issues in the period 2009-2010. But still, if the cats are shot, this should be possible to pick up by properly diagnosing the lambda readings? If not with OBD, at least using an oscilloscope.
Cleaning the injectors is also something I have read plenty about. But how does one differentiate injector symptoms from catalyst symptoms? Before considering a maniverter replacement I need to be sure that the cats are in fact faulty..