Alright, as promised...
ECT = Engine Coolant Temperature. This code means that your coolant temp sensor is shot, which means the computer doesn't know what temp the engine is at, which means it will run pig rich all the time as a safety precaution. This is why your car runs like crap.
The ECT is a little brass plug sensor located right about where the airbox is on the engine. If you look right below where the upper radiator hose goes into the engine, you should be able to see two sensors. The one to the left of the hose is the temp gauge sending unit - it's what tells you what the temp is on the dash cluster. To the right of that hose, and tucked away a little, is the coolant sensor. It is easy to replace... once you drain the coolant system and remove the airbox. Both are easy to do if you have the proper tools. To replace the ECT you will need teflon tape and a 1" deepwell socket. I would recommend replacing that temp sender as well (it's the one with one threaded thing sticking out) cos they go bad occasionally as well.
And while you're in there, you might as well replace that thermostat, which is probably bad as well.
As for the 121, that means your throttle position sensor (TPS) may be bad. The TPS is located right on the throttle body, across from the spring assembly. two phillips screws or bolts and it's out. And it's cheap. Replace it.
The 211 is the big whopper. PIP stands for Profile Ignition Pickup, and that's your Crankshaft Position Sensor, or CPS/CKP. This is where you start to understand why we say child protective services is comin' after you!
anyway, this is bad, as it means your CPS is going out on you. There are hundreds, if not thousands, of write-ups on how to change your CPS out, but the best one IMHO is right here:
http://www.shophoenixproject.com. Read and be knowledgeable!
And you said you know about the O2 sensor already, but make sure you go get a O2 socket from a parts store, or you will be cursing the day you tried to get at it!
Hope this helps.
