Hi All,

Well here goes my first post!

I'v got a 94 Volvo 940 with 98,000 miles on it. Recently I got the 1-4-3 check engine light notifying me of a problem with the knock sensor. I erased the codes several time, but the check engine light came back on.

Step 2, I replaced the knock sensor with a new Bosch unit. Reset the computer and drove fine for about a week before the check engine light came on again with the code for the knock sensor.

Step 3, I called a friend at the Volvo dealership and told him the scenario. He said it is probably the 2nd knock sensor unit at the rear/underside of the engine. Hmmm, is this true? Is there even a second knock sensor on a 94' 940 model? If so, where is it located and does anyone know the part number? Is the second knock sensor the same size/part as the knock sensor located under the intake manifold? The knock sensor that I saw and replaced was on the driver side engine block right under the intake manfold. Replaced that, and retightened to 10lbs of torque.

If there is a 2nd knock sensor, then that is probably the problem. If not, then what other options/steps can I take to get the knock sensor warning message to clear. I really don't want to take the car to the dealership.

Thanks for any suggestions in advance!!!

VolvoBiz