Hi, I am just about to replace the stub exhausts from cyls. 1 & 4 into the turbo section of the exhaust manifold. I had quite a struggle to remove them and had to use a torch to warm them up. I can confirm that there are no seals but the female pipe ends are a very tight fit into the centre turbo section and I am unsure if exhaust sealant was not used in the original assembly. Perhaps some kind soul can comment please... All the best. Boldv.