I recently had my wife's 1992 ES 300 serviced and about 10 miles after the oil change the check engine light came on. I checked the engine visually and saw nothing notable. The check engine light will go out overnight but will return after a few minutes of operation. I have tried to locate auto supply stores for help with breaking the code but they don't seem to have the right connector so I manually jumped the terminals per the manual. The code I got back is 5 5. That is 5 blinks followed by 5 blinks so I assume this is Code 55. On another web site with Lexus Codes, they say this is the KS Signal. I don't know what that is or where to find out what it is. Can anyone tell me what the KS Signal is or if what the 55 code means? We don't have a Lexus dealer nearby and I would like to try and repair this myself. I know that some codes are not readily fatal and the car can operate for some time with the fault but it does need to be repaired.

Upon more research, I believe the KS is the knock sensor and apparently it can be tested via continuity from the terminals to the sensor body. Does this sound right? Thanks for any assistance.