Hi guys, a few weeks ago I replaced my leaking injector oil seals. I removed the inlet manifold and had it cleaned etc. After putting everything back together, my engine check light came on. I got my local Nissan dealer to put their scan tool on it and it came up with EGR code found. They said I need a new egr and all gaskets and wiring harness to be checked as well. I bought a second hand egr from the wreckers and new gaskets and engine light still comes on. What should I be looking for apart from broken/melted wires etc. I’ve also replaced fuel, oil and air filters new oil, maf sensor cleaned.