You said you used the nissan gaskets??? If you bolt the dp's on to the turbos with the gaskets provided with the kits they will leak. The gaskets in the kit require you to bolt the seperator on top of the gasket, this makes the seperator to deep in the stock turbo housing and it bottoms out before the gasket can crush. I just did mine and it happend to me. So I put the stock gaskets on the bolted the seperator to the downpipe. This allowed the DP to sit flush on the turbo. Been there done that!