I have a E60 525d with the M57N TU engine that has had an increased emissions warning and reduced power warning but when the engine gets to 60 degrees the reduced power warning goes out. Increased emission warning stays. Reduced power warning comes back on when re-started from cold but not when still warm/hot. Pulled the codes using INPA 4212, 4222, 4232, 4242, 4252, 4262, 4501 and 93BD, D68E I have checked the the glow plugs and replaced two faulty ones (from an earlier code 4222, 4252) Checked electrical power at GP module. I have tried two replacement GP controllers (both BMW but not new - known to be working) EGR cooler, throttle body, EGR valve cleaned. It does have strong smell of diesel fumes wafting outside (know what this smells like as the stainless steel one was cracked and it smelt the same but since then I have put in cast iron manifold on) Need help on this one.