The headers are the ones from grp. I paid 699 for them or something like that when I bought the car. Don’t build a custom exhaust, use the stock mufflers they are pretty much free flow. Trust me. The J pipe (3rd cat) is like 199$ online, any unit will work, china garbage or expensive 3rd party...
I also removed all the underside plates, I have no idea wtf lotus was thinking, but I changed the bolts and painted them plates. Some of them had tarnishing and some rust spotting. I contacted lotus and they wanted me to bring in the car so they could replace them. It’s like 3 hrs away for me...
No, honestly I just ignore it and once every other gas fill, I pull the codes, I keep an obd2 in the car, if I see something I don’t like, like when the valve controller melted, then I worry.