Check engine diagnostic shows engine knock sensors bad and wants $1,100.00 to replace. is that too much?

Hello, the knock sensor won't cause knocking. It's job is to determine the best possible ignition timing. A failure of the sensor and related wiring is something that can affect proper operation -- but doesn't necessarily cause a running concern when faulty. However, I'd suggest a second opinion - perhaps try a shop near you for guidance? And a competitive quote? Also, you can check the estimator tool - www.repairpal.com/estimator and see if the parts are listed there. With the wiring, getting an accurate pricing quote may be difficult. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops