Scan data showed a misfire DTC and an active misfire on the engine. These engines, in both a Sable and Taurus, are notorious for faulty ignition coils. This custome decided to replace the ignition coil and plugs and wires (they were original).
Here's a look at the engine.
The front three plugs and wires are easy to get to. The rear plugs and wires are underneath the upper intake (plenum). The ignition coil is on the back side, underneath the plenum.
The ignition coils on these vehicles that I have dealt with that are faulty always have a crack at the base. The easiest way I've found to do a visual inspection for this is with a small mirror and a light.
I confirmed this coil indeed have a crack in it. To remove the coil and the plugs and wires I next got the plenum up and out of the way. I first disconnected the air breather hose and from the throttle body.
I just leave it on the vehicle over on the side.
I next remove the vacuum lines and electrical connector from the EGR DPFE, which is on the right side (passenger) of the plenum.
I then remove the EGR valve.
Next, remove the plenum bolts. There are eight of these.
Once they are removed, to save some time, I simply raise the plenum up and using a strap, I secure it up our of the way. By doing this, I don't have to actually remove it completely from the vehicle. Just be careful with the two hoses coming up and connecting to the plenum so as not to damage or break them.
Now that the plenum is out of the way, we can easily see the ignition coil and the rear plugs and wires. At this point, remove the rear plugs and the ignition coil with a torx bit.
Here is the ignition coil off the vehicle. The crack causing the misfire is visible.
Once the ignition coil and plugs and wires are replaced, simply torque the plenum back down and reverse the order of removal to reinstall. (The plenum has rubber gaskets, which should be reusable. Simply wipe them and the mounting surface clean and reinstall.)
After reinstall, I cleared the codes and took the vehicle for a test drive. The misfire was now gone and the vehicle was operating properly.
