[Blue Bowtie]

Fuel trims (BLM) at 128 might indicate the PCM is in Backup Fuel and Spark mode, a.k.a. "Limp Home" mode. You'll have an intentionally rich fuel mixture and no spark advance in this mode.

As a test, you can unplug the connector from the knock sensor and rig a 3.3KΩ resistor in its place, grounded at one end. The PCM will accept the 3.3K resistance as a valid sensor.

If the code can be cleared and operation returns to normal, the knock sensor may have failed. If that works, don't leave the resistor in - Replace the sensor.

From my memory only, if both sensors are disconnected the voltage at the KS circuit should be around 4.5VDC.