Picked up a high milage 96 GSR cheap, had a dead cylinder.
After some inspection I realized that a valve lock nut had came off an ex valve on the bad cyl, so I pulled the head to inspect. Found that valve was bent, and the others were in good shape, so I just replaced the bad one (maybe not the best idea but i'm pretty broke at the moment and 30 bucks was do able, 400 wasn't).

So, replaced the valve, threw on a new hg, timing belt and whatnot while I was at it, and now I am getting compression in the bad cyl, but im having idle issues and getting a good bit of smoke.

Car starts and immediately jumps to about 4000, then settles to a pulse between 1500 and 2800. Before, even with the bad cyl, it idled steadily at 1100, so I can't imagine a sensor just went bad all the sudden.

I've checked the connections and I can't seem to find a mix up.

All my past cars have been obd0, so i'm a bit unfamiliar with the sensitivity of these obd2 sensors.

Any ideas?

 

without doing a valve job that cylinder will have **** leakdown numbers, but, it should still run if you at least checked to make sure the valve and seats looked similar

the situation you describe is most commonly caused by a vacuum leak. if you pulled the IM and didn't analy clean the head and intake manifold before the new gasket went on that's one area they leak, the second is if you forgot to hook anything up and the 3rd is if you messed up any of the plugs

 

I'll pull the intake mani and clean it again, I wasn't too thorough the first time around.
Also, finally threw a code now, Map sensor, so this seems like it may very possibly be the problem.