SES light...Knock Sensor 3.3

[swigg321]

My friend has a 1999 Pathfinder, 3.3..she spend over $ 2500 on recent repairs.One item that was replaced was the knock sensor.When the tank is full, no light.When it gets to 1/2 tank or below. the SES light comes on.Any ideas are appreciated.

[jetroy240]

U need to know what the code is first. Knock sensor does not trigger the SES light. Sounds like an evap system code. Make sure ur gas cap is tight. Maybe u have an aftermarket gas cap?
Modified by jetroy240 at 11:36 PM 2/5/2009

[Chuck Tribolet]

On my '01 PF, knock sensor is specific to P0325, and secondary to several others.

In this case, what's the code? Get it read out. I don't think a knock sensorproblem would be a function of the fuel level. I'd be thinking fuel supply system.Maybe the fuel pump can't lif the gas up to the motor (that would be a REALLYREALLY tired fuel pump), maybe the fuel pump is sucking against a vacuum.(does it give a really big whoosh when you take the gas cap off? Little whooshis normal, they keep a slight negative pressure to keep the gas fumes in thetank and not making smog),