first ran codes tonite and got code 91 now is this the passenger side ego. sensor 2nd would this code cause a rich condition on that side.
also temp gauge quit working could that be from ect not working even though no code came up
and the temp gauge runs off of its own sender. it is a one wire sender behind the dizzy. the ECT is totally different and on the pass side. they have nothing to do with one another.
might try doing a balance test on the injectors to see if one is not working, and causing the code.
good luck.