Primary cats and p0432

[Pebblefeline]

Hi guys

My clk350
Has a bank 2 cat that is performing below efficiency p0432 and I was looking for a little advice.

I don’t have any symptoms like loss of power or a bad smell. The cat doesn’t seem to rattle.

I had an emissions test done and the results are spot on.

at this point I have swapped the downstream o2 sensors over and know it not the sensors.

my intake manifold pressure is good and isn’t leaking

my ltft on bank 2 is 4% and on bank one goes between 6 and 10% but my stft on both banks stays between 0 and 3 %

I am pretty sure the cat is the issue and they are expensive from Mercedes and not easy to find replacements elsewhere.

I have heard that material can be sucked into the engine if the cat is failing, is this true of the m272?

can an under efficiency cat damage the engine at all?

Am I an idiot to keep driving with a suspect cat and should I just suck it up and get them replaced with sports cats?

Has anyone got any experience replacing the primaries with sports cats from magnaflow etc? And advice welcomed

thanks for you help everyone

jae