Long time reader, first time poster... . I have a 2004 LSE V8 with 106k miles. I bought it 7 months ago as a 2nd car (at 103k miles), and it ran fine. It needed some cosmetic love, so I've enjoyed getting her back into shape (repaired and repainted the bumpers myself, detailed the interior, replaced broken trim, etc.). It soon developed a misfire on cylinder 6, so I combed this forum to learn everything I could about this car. After I serviced the car (oil change, filter changes, replaced trans fluid, filter, and gasket), I then replaced the heater control valve, valve cover gaskets, COPs, spark plugs, and checked all wiring (and cleaned out the spark plug wells). I also checked the fuel injectors. I used a NOID light to verify signals. I wasn't getting a signal on COP 6, so I took it to a mechanic. He verified that no signal was coming from PCM, so the driver likely was bad. The wires back to the PCM have continuity and no attenuation/resistance issues. This forum recommended S.I.A. Electronics, so I sent in the PCM. That's when the real trouble began. S.I.A. rebuilt the driver for COP 6 and #6 no longer misfired, but now cylinder #8 misfired. I rechecked my work, swapped around COPS, spark plugs, fuel injectors, but #8 still misfired. No signal from the PCM. I sent it back to S.I.A. THREE more times (twice on my dime) and they could not find any problems. This last time, they replaced the capacitors for #8 driver, wrote me a nasty note, I reinstalled the PCM on Monday and the LSE ran awesome for 80 miles yesterday. On the way to work this morning, it began misfiring again (flashing CEL). I left my OBDII reader at home, so I do not know the code yet. Can someone please lend me some guidance? Have I overlooked anything? I know I'll never recommend S.I.A. to anyone. This Lincoln is too nice to abandon. I'm a decent shade tree mechanic, but I'm about ready to call UNCLE. Please HELP!