Knock sensor location

Where is my knock sensor located on my 1990 toyota SR5 pickup. I need to replace my knock sensor is it hard top do it wont pass inspection check light comes on. First the code 032 came up for the mass airflow sensor. I replaced that now the check light still comes on and its reading 052 for the knock sensor.

How do I replace the knock sensor on this vehicle and where is it located

Where is the Knock sensor located on my 1994 Toyota Pick Up engine 22R-E?
2 WD Auto Trans.

Thanks.

Hi here is a knock sensor test I found in a manual:
1985-88 22R-E(T)
1. Warm-up engine to normal operating temperature.
2. Attach a timing light with advance indicator and a tachometer. Locate the Knock Control Sensor, (on the engine block), and ensure that the connector is secure.
See: LocationsSee Computer and Control, Knock Sensor, Location, Harness.
Fig. 210 Tachometer Hook-up

3. While operating the engine at 2,000 rpm, check the ignition spark advance and calibrate the timing mark to 0° TDC.
4. Using a wrench or small hammer, tap the exhaust manifold and observe the timing marks.
5. The ignition timing mark should move in the retard direction, depending on the intensity and speed of the tapping.
6. If the timing mark does not retard, turn the engine off and check the wiring between the Knock Control Sensor and the ECU.
7. If no problems are found, replace the Knock Control Sensor and repeat test procedure.
8. If timing still does not retard, replace the ECU.
9. Disconnect timing light and tachometer from the engine.

I did this test and could not get a responding retard spike. I noticed my advance on my timing light was around 40 deg to make it show at 0 deg on pulley. This was at 2000 rpm. This Toyota 22re runs a little uneven at idle(jumps from 750 to 740 to 760 rpm) and won't pass idle smog check. I have replaced the TPS in the past. My main interest is why does the timing not jump and if it doesn't why is there not a 12 code in the computer? What is the computer expecting to see from the knock sensor? Thanks

Thanks, so all the knock sensor does is retard timing, no A/F mixture?

I rented a Fuel pressure tool and will tackle Friday. Thanks.

OK the fuel pressure is as stated in manual. 38.0 psi not running, 37.0 psi running no vacuum on regulator, 30.0 psi regulator with vacuum, and 35.0 psi after shut off for 5 minutes. I adjusted the valves because they were too tight and could not set idle a few months ago. I am using a heated O2 sensor on suggestion of LC engineering the maker of my headers. Plugs and wires, cap and rotor have less than 2500 miles on them. What could be causing the uneven idle which I believe is over rich? Thanks

Only headers and a K&N drop in air filter. Completely stock otherwise. What the way to check vacuum leaks? That works? Spraying carb cleaner on hoses and gaskets I can never when the engine surges. I haven't tried with tach connected. How much of an rpm surge should I look for? Thanks