Worth trying upstream fixes first as omar referred to earlier - plug change, coil change (or at least resistance verify), Techron Concentrate Plus or BG 44K, even Cataclean. MAY clear up on its own may not. If the problem originated upstream, which is very likely, then the new cat will go down the same road. Pulling the plugs will at least tell you whether this approach has value.
When you are tuned and revert back to stock. Soft codes are thrown (Forscan can remove them) though your miles since flash, key strokes since flash...etc etc all reset back to 0. So if Ford wanted to be picky and you come in with 10,000 miles and 2 key strokes, they know somethings fishy. With all that said. I had a cracked transmission housing and after 6 long months of my car at the dealership back and forth saying they fixed it and it was still leaking. My car went in with the tune on it and they replaced my housing as they said it was irregular from the factory. Livernois has the fastest Edge Sport in the 1/4. You wont be disappointed with them and is probably a 100% better option than the JMS product
Update - had the code scanned and it came back as a catalytic converter - bank 1 which I believe is the catalytic converter on the firewall side of motor - just below the exhaust manifold.
Apparently the theory is that under light load - as in exactly how my wife drives all the time - the exhaust is able to exit no problem. When lead foot me steps on the gas - the additional accelerated combustion can’t exit through the converter fast enough and effectively causes a misfire because the fumes are slowed down from leaving.
Garage said $800 for that converter - I’ve checked online at places like Rockauto and I can get it for about $300 delivered to me. Not sure who is going to do the install now - as I’m not willing to pay a shop an extra $500 just for ordering the part from their local Napa or carquest.
So is this converter a DIY type of driveway repair or do I need a lift and torch to swap it in ??