Status Gruppe Tuning / SGT Cats

[George Hill]

I've got a S54 Z3M in my shop and I am working through some things on it and looking for some insight from the group.

The car has an SGT catted sec 1 on it and it has cat efficiency faults stored. The cats are identified as being made by Magnaflow and between the two of them I have 0 experience with this setup.

For those with these cats, will they set cat efficiency faults on a stock tune?

I've used Magnaflows on S62s and they almost never pass the cat test, I wasn't sure if that was the same with these as well.

If this is "normal" I've got some options to fix it just wanted to see if this is a known issue or we really do have a cat problem.

TIA

********EDIT
2nd part is does anyone have pics or know how the rear O2 sensor wiring is routed? I've been scouring the internet and can't find a definitive pic. I think it should go up the RH side of the transmission tunnel to the e-box, but I am not sure.

[Slideways]

Does the car have aftermarket headers? I am assuming it does; otherwise, it would not have this issue with the factory headers.

With headers and the SGT catted section 1, it will set cat efficiency faults on a stock tune. The SGT catted section 1 uses 200 cell Magnaflow cats. Stock is 400 cell HJS/Emitec on the factory setup.

[George Hill]

Yes, it has headers.

[Slideways]

Not sure if this will help, but Evolve installed a set of Supersprint headers on a Euro S54 Z3M -

[George Hill]

Super helpful!

They are routed like an E46 which is interesting since the DME is on the RH side vs the E46 being on the LH side. So the wiring crosses the engine, runs down the drivers side of the tunnel and links up to the O2s.