Received the ARROW DECAT today, nice piece !! My issue is this continues to loom over my thought process on installing it....( source below Coober eu) Picture 1: Arrow De-cat. It is a good quality product, nice welds and fits good to the mounting spot Picture 2: As expected the 790 Engine wont allow any de-cat. Here we can clearly see and confirm what @kobi.liany already did with his 790. After a while the 790 goes in to the protection mode. This is a known feature from Bosch and mainly developed to protect the engine. Picture 3: Here we can see stock, vs decat, vs, coober ecu with decat map. The bad news first, we are not going to release any de-cat map for the 790 and the reason, you can see at Picture 4. Even if we can override closed loop and do whatever on fuel, ignition, traction, torque ... but in fact no serious company is going to sell you something useless. Does not make sense at all, when the simple ecu setup is making more reliable power on stock setup. Picture 4: Oil results. We got a chance to compare those results, with the older one from a simple pipe decat solution. Well as expected benzol gets more. This is a very well know issue on the 790. This happens if you disconnect your lambda, or if you flood your cylinder with fuel in lower rpm, or simply if you have no clue about thermodynamics Picture 5: Heat, for those who understand the function of the cat converter. the 790 engine setup is made to have a thermodynamic management with cat-included. The info in pic 5 shows the difference between stock and decat in heat management under identical conditions. This makes it bit more clear why the stock es is fighting back sooner or later. Conclusion. We love the 790 Engine. Very proud to be apart of its existing, but de-cat is still nothing that we would recommend. In fact no serious company is going to recommend it ever.