I have a 2000 DII with 112,000 miles. After getting Bank 1 Sensor 1 errors along with cylinder 5 misfire I changed out all 4 oxygen sensors with sensors from Atlantic British. This fixed the O2 errors but did not fix P0305.

At 91,500 I had a slow coolant leak and was getting P0307 Cylinder 7 misfire codes. I installed new head gaskets, 8MM Magnacore wires, Bosch +4’s. After I got everything back together I still had the misfire so I they went in a replaced both coil packs. Everything was good until I got the O2 error.

It started off with about 100 miles between getting a code. I frequency is getting shorter and new troughs a code at about every 50 miles. I put a can of Seafoam into the gas tank to see if cleaning the injectors would help. Yesterday in addition to P0305 I got P1300 and P0308. I got the truck at 81,000 and have always used premium gas. Any ideas on what I can do next?


Thanks,
BIG g

 

Have you pulled both the # 5 and 8 to see what they look like, do they smell of coolant?
Might want/need to do a compression test to rule out any bad valve issues.

 

Mike,

I pulled plug 5 and it looked fine, no signs of coolant. I actually put a brand new plug back in and still have the error codes. I only have gotten the code for cylinder 8 once, so I did not pull that plug yet. When I did the head gaskets I took the heads in for resurfacing and they checked the valves at that time. I know that it doesn't mean that it can't be bad now though. What is good compression range?
I don’t really even notice that it is misfiring. I'm I hurting anything by driving it?

 

If you don't figure it out, send me your number and I'll call you.