Some codes make CEL at once, others wait two or four drive cycles to pop back up (pending).

 

So I installed new E3 plugs and replaced one of my spark plug wires. Still have the same codes. Leaning more and more towards faulty coil. I still get codes for both primary 02 sensors. I bought the bosch direct fit from advance so no splicing. I will install those in the morning to see if maybe that could have something to do with the misfire although I feel like the previous owner driving 70 miles a day with a misfire is probably what ruined the sensors, not the other way around. Nevertheless, I will replace the sensors first thing tomorrow and report back. If that doesn't work then I will wait for the magnacore wire set to come in. I am so tempted to get coils at the same time since I will be right there replacing the wires.

 

Update:

I installed both primary o2 sensors with the Bosch direct fit (advance auto parts, 75 each used a coupon to get 40 off 110 order so 110 total)

Both o2 sensor codes are gone. I have STI wires on order and went ahead and got a used set of coils. I replaced all of the plugs with e3 and got a cheapo set of wires to test with. I only replaced the cylinder one wire. I still get the 1300, 0300, 0301, and 0306 codes so the plugs and the wire did not repair the issue (at least with cylinder 1).

I am still getting only those codes and usually the 0301 and 0306 will show up twice. Now I randomly get a 0305.

I will replace the coils and install the STI wires this weekend then update this thread. Mike also recommended a compression test so I will post those results too.

 

I'm definitely curious to hear what the problem turns out to be.

 

Well today worked out for me and the Discovery. I ordered new STI 8mm wires from ebay, $37 shipped and also got a used coil (it was actually both coils) for $45 shipped. It took me about 2 hours to remove the old coil and plugs and replace with the new parts. It is possible to remove the coil without having to remove the upper intake manifold.

The truck runs great now. No more misfire codes! I still have the 1590 but I will tackle the three amigos another weekend. My guess is that the coil was going bad causing the 1 and 6 misfire and that the cheapo wires it had could have been at fault for the cylinder 5 misfire.

 

Nice job. It always feels good to fix something. And I've had that good feeling often since I got this truck.

The three amigos can sometimes be very simple to fix. The problem is you have to have an ABS Amigo to read/clear the abs codes. I rented one from a forum user named exploringnh, and it worked great. You'll need a pc to pull the codes off the Amigo.

But if it's the shuttle valve switch or the connection to the shuttle valve switch, it's simple stuff to fix. My switch was bad (which you can actually test with it in the truck), but it was a bad solder joint inside the switch, so I was able to repair it. The only expense was time and ABS Amigo rental.