We all know how the engine wire harness near the EGR valve is susceptible to damage, but there is another area that is at least worth a look. Part of the main engine wire harness is routed very close to and is likely touching the glove box reinforcement bracket as it takes a hard bend out of the ECU. This bracket can rub through the vinyl tape around this wire bundle, through wire insulation and cause a wire (or wires) to short to ground. This happened to the #4 fuel injector wire on a previous cruiser and left me stranded on the side of the highway over 100 miles from home. The fuel injector shorted to ground, flooded the cylinder and caused a misfire on cylinder #4 throwing code PO304. I believe it is less common than wire insulation damage near the EGR valve, but it has happened to several people on this forum.
Initial symptoms were persistent shaking and bucking that worsened with increasing RPM. Check engine light came on and scan gauge showed code PO304. I didn't have my FSM with me and couldn't do any troubleshooting so I had to be towed home. That was the last time I traveled without the FSM. The local dealer couldn't get to my car for 2 days and I was able to fix the problem on my own thanks to this forum. I repaired the damaged wire insulation and padded the problem bracket. Once I burned off the extra fuel and smoked out the neighborhood, the cruiser ran fine.
I decided to preemptively pad this bracket on my current cruiser before it caused any trouble. It seems to be an uncommon issue, but it takes little time to fix. If you open a beer before you start, it will still be cold when you finish.
You'll need to remove the glove box, the passenger dash speaker cover and a few bolts to allow the suspect support bracket to rotate down for remediation.
First remove these 4 screws, glove box and speaker cover. The speaker is connected to this cover and needs to be unplugged.
You can see the bracket has been rubbing on the wire harness, but has yet to get through the outer layer of vinyl tape.
Then remove 4 bolts (one bolt missing from picture) and swing the bracket down to work on it. There is a fifth screw affixing the bracket to the left side of the dash that it will pivot on.
Pad the bracket. I used a small piece of rubber tape and affixed it with standard electrical tape so as not to add bulk to the front of the bracket. You could also grind down the bracket to reduce this hump. You may be able to grind it enough so that the wire harness no longer touches the bracket, but I do not know as I did not go this route.
No more sharp edge. Install the 4 bolts, glove box and speaker cover, 4 screws and your're done.
Search Keywords: Misfire, engine shaking, PO300, PO301, PO302, PO303, PO304, PO305, PO306
Initial symptoms were persistent shaking and bucking that worsened with increasing RPM. Check engine light came on and scan gauge showed code PO304. I didn't have my FSM with me and couldn't do any troubleshooting so I had to be towed home. That was the last time I traveled without the FSM. The local dealer couldn't get to my car for 2 days and I was able to fix the problem on my own thanks to this forum. I repaired the damaged wire insulation and padded the problem bracket. Once I burned off the extra fuel and smoked out the neighborhood, the cruiser ran fine.
I decided to preemptively pad this bracket on my current cruiser before it caused any trouble. It seems to be an uncommon issue, but it takes little time to fix. If you open a beer before you start, it will still be cold when you finish.
You'll need to remove the glove box, the passenger dash speaker cover and a few bolts to allow the suspect support bracket to rotate down for remediation.
First remove these 4 screws, glove box and speaker cover. The speaker is connected to this cover and needs to be unplugged.
You can see the bracket has been rubbing on the wire harness, but has yet to get through the outer layer of vinyl tape.
Then remove 4 bolts (one bolt missing from picture) and swing the bracket down to work on it. There is a fifth screw affixing the bracket to the left side of the dash that it will pivot on.
Pad the bracket. I used a small piece of rubber tape and affixed it with standard electrical tape so as not to add bulk to the front of the bracket. You could also grind down the bracket to reduce this hump. You may be able to grind it enough so that the wire harness no longer touches the bracket, but I do not know as I did not go this route.
No more sharp edge. Install the 4 bolts, glove box and speaker cover, 4 screws and your're done.
Search Keywords: Misfire, engine shaking, PO300, PO301, PO302, PO303, PO304, PO305, PO306
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and I rewrapped the loom and since I didn't have any rubber I put a pretty thick layer of duct tape on the metal side and rerouted the stereo wiring up and out of the way 
