2000 sl2 o2 sensor

The wife calls me today and says she has a SES light on again. I told her to get the codes read and call me back. Had two codes, one is P0133 and the other is P0301. The 301 was still in there from the previous vaccuum leak problem that I fixed but never got the code reset (at least I'm pretty sure and am working under that assumption). Now, the 133 indicates upstream o2 sensor responce slower than minimum yada yada yada. I'm assuming upstream is the one on the front of the engine at the manifold not past the cat. She had them reset and so far they have not come back but she only went a few miles. So, the car has 130,000 mi and they have never been changed. Should I just go out and buy it and change it out or wait and see what happens.

Any specific recomendations when I change it? How difficult should it be, etc?
Thanks again:iceslolan

practically anytime that is thrown, the o2 is bad. its a simple replacement. you can just use a 7/8 wrench on it and get it out. putting the new one in, make sure it has anti seize on the threads (make sure it doesnt touch the tip of the sensor or it could ruin it). now it doesnt need to be uber tight, just snug up in there.

now my suggestion would be drive it a bit more. one thing to try is get hard on the gas one time, not meaning to spin the wheels, but like already moving smash the gas and see if the light comes on. ive had that code several times and found taking it easy my car wouldnt throw the code, i get on it a bit more and it would and if i smashed the throttle, the code was on in an instant.

Thanks for the info. Light hasn't come back on and I'm broke because the university decided to change our pay periods so now I have to wait longer to get money. Oh well... if it comes back I'll just buy one and stick it in. Do you recommend dealer parts only for this sensor?

i would definitely suggest dealer part. of course im sure it will be like $70 area, but your lucky since its a 1 wire you could buy a universal one thats like $20. i bought a cheap bosch oxygen sensor and seems to be fine since i didnt have the money to get the stock one. bosch spark plugs are junk but the oxygen sensors seem fine.

but i suggest dealer part, but the bosch oxygen sensor seems to work fine. so you can save yourself some money and just get the universal 1 wire one if you can wire it in properly which i think it comes with everything needed. i would rather have it soldered in but the butt connector works fine too which is what i think it comes with.