However, you'll generally find it mounted on the engine block, near the cylinder head. It's usually a small, threaded sensor with a single wire. To locate it, you'll need to:
1. Consult a repair manual: A Haynes or Chilton manual specific to your 1990 Toyota 4Runner with the correct engine (22RE or 3.0L V6) will show the exact location with a diagram. This is the most reliable method.
2. Search online using your specific engine code: Use a search engine like Google or Bing and search for "[Your Engine Code] 1990 Toyota 4Runner knock sensor location." This might yield images or forum posts with pictures.
3. Look near likely areas: Focus your search near the cylinder block, especially areas where the block is relatively flat and accessible. It's often near the distributor (if your engine has one) or other sensors in that general area.
Important Note: Before attempting any repair or sensor replacement, disconnect your negative battery cable to avoid electrical shocks or accidental damage. If you're unsure about working on your vehicle, consult a qualified mechanic.
