SES light won't go off even after having it serviced, please help!

[lala08]

Hello I am new to the site.
I have a 2002 Oldsmobile Alero. 4cyl engine w/ approx. 100,400 miles.
The SES light came on in October, the diagnostic from the mechanic indicated that I needed new O2 sensors so I had both replaced w/Bosch ( I think they are premium, 4 wire, heated if that helps) oxygen sensors. I bought the recommended sensors at Autozone and Pepboys installed them. AFter about 3 weeks the SES light came on again. I took it back to Pepboys and they said that the sensors were fine but probably since they are not the dealer brand they are setting off the SES light. I finally decided to let the dealer check it out today. They said that the rear sensor was loose and not inserted properly. THey reinserted it and reset the light. 10 minutes after I drove off the SES light came on again. I took it back to the dealer and now they say that the rear O2 sensor is damaged(they didn't seem sure) because it wasn't inserted properly and I was driving around w/it. The dealer can replace the sensor but it costs $170 (that I don't have) plus labor. Pepboys is refunding me for the installation fee but they aren't liable for the part since I bought it from Autozone. The dealer didn't seem really sure if the sensor was damaged and I'm not sure what to do. ANy suggestions would be appreciated. My emissions inspection is coming up and the SES light can't be on or they won't even test the car.

[Hungrycat7]

Well my first suggestion would be to stop taking the car to a dealer! All they will do is rip you off! You need to find a mechanic that you trust! Also you can take the car back to Autozone and they pull pull the code that is setting off you Service Engine light! (Usually for free!) They should also be able to reset the code with the scanner! This is a very common code! You already paid the stealership so you need to insist they fix the car right! You took it in to get it fixed and they obviously did not fix it!