Hi I have a 2002 Octavia vrs auq 180 which has a secondary air punmp delete a 200 bhp remap before a De cat 571. Forge tip walbro 255lph Fuel pump. the car was irritac to say the least poor idle very low mpg . Like 8mpg. Running very rich. Occasionally overtaken by clouds of black smoke. Plugs coking after 3 mins on idle. I have replaced cts mad plugs and it's not a coil issue this is established! I am wondering if the 50/50 dump valve has caused the massive overfueling issue? Due to the fact the air loss through the dump valve is cold side relocated. recirculation inlet in tip is after the maf.? I have had the ecu unplugged and no signs of water damage or ingress. Replaced the cat lamda and have secondary one on order? No combination of parts improve reliability or longevitey bit running costs are high. Almost considering a diesel at this stage., any ideas?

with so many mods is very difficult to say what;s wrong