I have a 02 7.3 PSD that is running like it is missing in one cylinder, and it has lost allot of power. I checked the filter and it was black with a fine sand like sediment on the top. I changed the filter but it runs no better. the second time I took out the filter I ran a magnet over the particles and some of the particles are magnetic. I think the particles are too large to fit through the pickup screen in the tank(though I'm not certain). Where are the metal particles coming from? If it is running like it is missing would it be an injector, injector seals? Where should I look next? I just took a laser temp reading of the exhaust manifold by each cylinder(F): drivers frount- rear 70,148,172,171 passenger Frount - rear 166, 186, 170, 158. It seems the drivers frount is way out compared to the rest.

It has a DP Tuner, 4" exhaust and cold air intake. 167,000 miles