tighten your gas cap, then leave the battery cables off over night and it should clear right up. if not, then your 02 sensors are bad......again. they go bad all the time. i bypassed mine with a sensor cause i live in the humid south and my ram runs lean because of this. if you live where it is cold then you maybe running rich. if an 02 sensor is off by.2% then it will cause a fault. correct air/fuel ratio is 14.1% and its nearly impossible to tune a fuel injection motor to those specs thus causing the 02 sensor to default
after driving it for fifteen minutes it turns back on
Assuming you mean the egr valve, I would make sure that you have the check engine codes cleared. In addition, are you sure that it was truly the egr valve, and not the DPFE sensor monitoring the valve?
Faulty sensor get it replaced if not check to make sure wire isn't shorting out
your knock sensor could need to be replaced
Be sure to check the wires going to the IAT sensor. Nissan used cheap wiring for this and it usually breaks. The problem is the wires constantly flex when the engine moves.
I had all sensors replaced in my 03 Trailblazer and the check engine light stiil comes on. Why?
How do you know the gas cap is responsible for the Check Engine light? The computer will have to be cleared by a repair shop with a scanner.
If your vehicle has a bad sensor the check engine light will come on. Otherwise they should be replaced as recommended by your service manual.
Could be the knock sensor.
Not sure if this will help but try this answer on another site. http://answers.yahoo.com/question/index?qid=20060623092709AAKy5vf
There are 2 knock sensor on the 5.3L engine. And they are under the intake manifold. To get to them you will have to remove the whole top of the engine- INTAKE MANIFOLD. Why do you think they need replaced???? check engine light came on for 2 sensor
I have a 98 mystique, and when the check engine light comes on, I simply disconnect the positive battery terminal for a couple of minutes. When I replace it, the check engine light is cleared. It resets the computer.