I have a 96 maxima with 150,000 Miles on it. The check engine light has been on and off since I bought the car with 90,000 miles. Now I have to pass emissions and they won't pass a car with a check engine light on. I checked the codes and they were Knock Sensor and EGR Valve Solenoid. I purchased both and replaced the EGR Solenoid. Started the car after that and found the light stayed off. The next time I went to start the car the light came right back on. Checked the codes and EGR Valve Solenoid, Knock Sensor and A/T Control Unit came up. I found this strange because I have a Manual Transmission. I have heard from several sources that the Knock Sensor will not cause the Check Engine light to come on but it seems this is the cause of the problem. I tried checking the continuity with an ohm meter but either the sensor is dead or the ohm meter is not sensitive enough. My next step is to install a new Knock Sensor but because it's a rather pricey part I would rather not do this if it is not the problem. I'm also starting to think this is not the problem because the EGR valve Solednoid still comes up on the ECU. I am also planning on cleaning the air intake filter and throttle body. Any ideas????

 

Cleaned the Throttle Body and Air Intake today but I am still getting the codes. I am ready to give up, please help.

 

Anyone have a good test for the knock sensor? If I unplug the harness and feel no change driving around that should mean its bad right?