I cant locate the possiable leak I have removed the o2 houseing gasket due to running a o2 Dump since it caused the car to run wacky A/F and was messing with the o2 sensor. I used Copper Gasket maker as I know the RTV will burn away but the copper seal will be there. I replaced the copper exhaust manifold gasket back with a OEM with the new Tubular mani the DP is the only one but I used copper gasket since its bright orange around the edges and no blackness yet and i also checked the Test Pipe to Downpipe gasket and its fine.
I would love any help also the Downpipe is some weird off brand it says t-bros it does not use the oem donut gasket it has a pre fitted one for the o2 houseing to sit into it I used gasket maker there to seal it on both the o2 and the Donut/prefitted one.