I haven't been able to check out a whole lot due to Michigan weather and I'm in the middle of moving. The one code I get is "insufficient egr flow". Replaced every part of egr system. Still getting the same code. So I don't know. Really bad idle to the point of stalling. No vacuum leaks. I checked out tps voltage did not meet specs, so I installed a new one. Same voltage and idle problem, so I increased idle using the adjustment screw, ( which I know is a big no-no, but I needed the truck). Did major tune up over the summer. I mean major. New plugs, wires, coils, injectors, Idle air solenoid, EGR valve, EGR vacuum control, EGR transducer, TPS, vacuum lines, mass air flow sensor. Disconnected computer cleaned both sides of connectors with electronic cleaner, then cleaned with toothbrush, new timing belt and CPS, all of these things and no difference. I want to check compression and found #3 is more than 10% off put a little oil in cylinder, it was slightly better but still more than 10% off. The only thing I haven't changed is computer, that could be next but I'm thinking the motor is just tired, I know I am. #3 cyl has always been low since I got the truck, but it ran well, now not so good, never burned oil or lost antifreeze, still doesn't. I don't know exact PSI of cylinders because I wrote them down in old garage and lost them in the move. Once I get settled here, I'm gonna pull valve cover and check for stuck valves etc.