IMO Crimp connectors if done correctly are as good as soldering. You can electric/f4 tape them or use shrink tubing. We use crimping for 90% of our repairs on the planes. But if you do solder in and engine bay use silver solder. Stands up to higher heat.

 

Using the butt connectors wasn't the problem. The problem was that they didn't push the wires all the way in and the only crimped the plastic. I pushed the wires all the way in and did 3crimps. One on each end, on the merely and then on the center to ensure a good connection. If done right, crimping is fine. And if your budget is low it's the better than just Twisting the wires together. As with any repair work, the repair is only as the job you do!

 

In certain situations, crimp connectors are perfectly acceptable. I just don't think that the hostile environment under hood is one of them. Heat, cold, moisture and vibration (not to mention the normal oxidation process that occurs between dissimilar metals) will take their toll on the crimp connectors and they will fail. The resistance introduced by the weakening connections will skew the signals being sent from the sensors to the PCM. Then the mysterious electrical gremlins will return. I have seen this scenario play out numerous times over the last 30+ years being an ASE certified mechanic. To each their own, but with JC's intention of keeping the car for a while it just seems to me a more permanent repair would prevent future headaches and the need to revisit the same problem(s) when they pop up again.

 

Mike, I hear and agree with you. I would much rather have soldered the connections and know I will be in there again. But at this point I had no funds and needed to stop the RPMs from jumping up to 2000 every time I hit a bump. Now that I have done this, all my CEL codes are gone except for the O2 sensor bank 1. And I expected that one when I had to replace my Cat a few months ago. In the spring I can go in, solder all the wires one by one and use heat shrink around the connections. But for now, I need to know the car will last through the winter and the NJ. Inspection in Apr. At this point, electrically, now I know it will.
My best solution is to completely replace the harness. But I can't do a Junkyard Day until the spring. The closest Big ones are in Pa. They would be my most likely source for a complete wire harness for an Old2 Monte.