Because this is my daily driver, (yes, I know, crazy), I just ordered new pre cat and post cat O2 sensors. Will be here tomorrow. F it, $100 is no problem.
With the above advice taken in I also did research last night on 2,4,6,8 misfires and found that in fact a bad O2 was the issue in most cases. There is also the possibility that I have a bad cat on that side being I have a P1300 code. (?)
Any other advice welcome.

 

Dear diary... Haa

So, dry windy, and cool night and day. The 2001 D2 is running great, throwing no codes this morning after a 45 min drive on back roads and cruising at 68 on a highway. I did though check both O2s on the one side to make sure there had been no damage and that the connections were good. Found no visible issues, ... but maybe an invisible one that was corrected just by moving them around. (??)
Oh well. I bought this knowing this would be my life from now on. haa.

 

Downstream O2 won't cause a misfire; doesn't control fuelling. Replace your plug wires. If it's happening only on wet days then you have a short somewhere and plug wires are common.

I disagree with the sentiment of replacing the O2s as a first attempt. Coils, plugs, and wires are cheaper by quite a bit. The cheapo eBay coils work fine and neither plugs not wires cost much.

 

the wires for that side are not on the same coil, so with those symptoms if it were the coil pack, all cylinders would be misfiring or it is highly unlikely. You could inspect the wires and with that type of result you’d think you’s See damage in all of them if it were the wires.

Getting O2 sensors on and off can require heat. I broke the o2sensor socket not using heat. So just swapping them is not easy, but if you have acetylene go for it.

I’d either get a tool to track the O2 sensors output, or have someone do it before throwing parts at it.

 

Can anyone please confirm that my bluetooth tool means U.S. Driver's side (left side of vehicle) when it says O2 Sensor 1 Bank 1?

 

Yes left side is drivers side.

 

II ordered a WiFi Borescope today. I think I know the real issue here. I need to get a new motor ready for Springtime install. Hoping to get through the winter on this one.

 

Some results, ... that I'm hoping are final.
Decided to flush out my cooling system the other day. It was then that my eye picked up a tiny lightening bolt. Yes, #4 plug wire was arching onto the valve cover. Found a tiny crack in it and taped it up and shifted it away from any ground point. YES, .. the D2 ran great. Then later I felt another slight misfire. Code read #8. Could not see any arching, but did my best to make sure connections were good and the wire was as clear from a ground as I could. It did seem a bit pinched. Just drove to Boston and back (about 3hr total) and no codes, and much better fuel mileage. We will see how long this last, but I do believe I have solved the 2,4,5,8 misfire issue. Figure I was running a large amount of raw gas into the exhaust, freaking out the O2 sensor, which was maybe leaning out the fuel enough to make 2 and 6 misfire.??
Will order new 8mm wires tonight. Might as well do the coils also.

 

So , I can confidently say that my #4 and 8 plug wires were the issue. Not the O2 sensor.

 

How old were your wires?