I was given a quote of 950$replace 2knock sensors/ air fuel ratio sensor 2much?!

Hi and thank you so much for responding. No I have n ot got a second take on it yet am in the process of trying to find someone to do it at a reasonable rate, They only charged me $25. For diagnostic. They stated all 3 sensors were bad and needed replaced and possibly another air fuel ration sensor may need to be replaced after these three are replaced but they stated they wouldn't know if the other air fuel ratio wAs bad until they replaced these 3..????? Help

you know I have never had a car where all the sensor are bad, just 1 or two, may you need to ask what is the fuel trim is at. is the system running rich or is running lean this will flag a check eng light and some shop will replace the 02 sensor, when in most of the time in my shop we find there is a vac leak

Ok thanks I will ask when I have it in for a second look I am going to call a few places today to see if they can get it in and looked at for lower diag. Charge. Thank you very much for your time I appreciate it. Please let me know if you can check it at a much lower rate. Thanks again.