Oxygen sensor code 1222, and bad CAT ?

[Banditt]

2 Questions:
1) My 90 525i E34 is putting out Code 1222. 159,000 miles. It, seems to take a while to put code out 5-10 minutes. Was flashing yesterday, now it seems to be more sticky. Acceleration, or deaccelration seems to turn check engine light off. Jut before this happen I did, take out the Oxygen sensor in preparation to replace it. (I wanted to make sure I could get it out, which I did with little difficulty).
Did I damage the oxygen sensor by removing it? I looked in my service guide 1221 means oxygen sensor, 1222 means oxygen sensor regulation. SO does this mean the sensor is juming around with it's voltage readings. When I first took the O2 sensor out, the voltages flucuated between about .8 at idle, and .2 when reving. I thought correct I have not re-measured voltages. Any ideas please on what to do. The car runs rough at idle.
2) I failed prior to messing with the O2 sensor, I recently failed emissions, I had the CAT checked it measured about 525 degress at input, and about 375 at output. I was told the CT is bad. My nitroius Oxide is failing, and Hyrdo Carbons failing emissions. The Nitrouis Oxide is really high. Is the diagnosis on the CAT correct?
Thanks

[wsill]

We did more research last night. We found an a slight air leak under the throttle postioning value, the boot was loose. This only helped slighty. Also the pvs pipe, from throllt cavity to the top of the manifold is "deteriated" on the ends, we cut off some of the ends, and reclamped. I plan to replace.
But:
Now the O2 sensor reads only .2 volts, and actually drops on acceleration. I'm beginning to think I damaged the O2 snesor removing, and reinstalling. Though not sure how possible. Does anywho have any ideas on how the O2 sensor could be damaged on removal & reinstall. I gor the O2 sensor out, without too much struggle.

[Jared at Pelican Parts]

Has the O2 Sensor ever been replaced before? I'm thinking it may have been bad to begin with. I know it will cause some slight driveability problems if it is bad. Sounds like you may also need to check for vacuum leaks around the whole engine. I had a lot of idle, acceleration problems that were all fixed by replacing all the vacuum hoses.

[vitifonz]

Would radical engine reving going up/down when car is parked be any cause of a bad Oxygen sensor/or vacuum leak? Just happened this morning...i can't figure it out!!!!!

Thx...

[Jared at Pelican Parts]

viti, I would first check to see if you have any loose vacuum connections int he engine compartment. An O2 sensor typically will not cause "radical engine revving" You probably have a loose hose somewhere.

[vitifonz]

Thanks;But sudenlly everything back to normal

[Jared at Pelican Parts]

You have a loose hose somewhere..

[vitifonz]

I'll be checking all hoses this weekend...BTW I have 3 green bars left and I added 1qt about two weeks ago; Should I do the oil chg now or just wait for all bars go out???

[Jared at Pelican Parts]

I would wait. You probably still have some time to go. I'd be wonderign about oil consumption.