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1990 What did I just break? (That wasn't the coolant temp sensor)
I sure could use some help!
My 1990 LS400 stalled in traffic. I checked and it throws up an ERROR 22 (OBD-I) which is the "water temp sensor signal." I guess that has something to do with the EFI system (it revved really high and kept dying).
I looked up at a DIY online, I felt confident I could change it. My mistake was trying to do it at 12:45 AM so I could have the car for work in the morning. I spotted something that (turns out) is NOT the temp sensor after all, despite being directly above one of the hoses. In the process of pulling a vacuum line off, I broke the part the vacuum hose slips on to entirely. I have no idea if the car is safe to drive. I have no idea what I just broke. I have no idea what to look up how much it costs to replace. HELP! lol
And regarding your problems + code ... I've found that these cars are designed to deal with failed parts very well, and it would not make sense (in my opinion) for just a failed coolant temp sensor to cause the running problems you're having. Especially since the ECU "knows" about the bad sensor. A smarter decision would be to do the best it can without using info from that sensor (e.g., when the AFM - a much more critical sensor than ECT - is unplugged, it runs fine without it), and I'd bet it is programmed to do that somehow (just a guess, though). A coolant temp measurement does not seem critical.
So anyway, I'd start thinking and looking for some other problem that could be causing your running problems and also the ECT sensor to be failing.
And in general, if most of the plastic and rubber have been doing their job untouched for 20+ years, expect a few breakages like that when you need to get in there.