Few small problems and three codes.

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2006 Mazda3s 2.3l
Hullo all. Problems started with a rough idle so I cleaned the TB which didn't seem to help. Still feels rough, and the acceleration feels off. Takes a second or two for it to really kick in, and after I left off, it takes another second or two for it to feel like it stops. Kind of a soft jerk sort of. Anyway, I'm getting codes p0131 and p2251 which I know means I need to replace my upstream 02 sensor, so I'm already working on doing that. I'm also getting p0661 which I know is a solenoid from what I've researched. Question is, does any know where I can possibly find this anywhere at all? Looking online has been no help at all. Could all of this be part of the idle and acceleration problems? Thanks a lot for the help. Also, just in case it helps, it's around 142k miles.
 
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