so had an engine knock since i bought the landy about 2 months, been going through bits and bobs to make sure everything is good, however ive got a knock, i had the hose pipe out and listened round engine bay and checked everything i had found in this forum, but in the end i found it was coming from the second exshaust port on the manifold, now im 90% sure its not a gasket issue on the manifold, im suspecting its an injector fault, what do you guys think?