P0100 and P0325 nissan altima

I replaced the MAF a week ago but the code P0100 is still there. Car runs fine in the highway but I do notice acceleration issues. I got the knock sensor but I cannot find it in my nissan altima (2000). The car shakes while stalling, at a red light, and pretty much as soon as I stop. Putting the car in N will help a bit but won’t stop the shaking. Should I focus on the MAF again or should I keep trying to replace the KS? Any idea of where it is?

If you go to this website http://www.ehow.com/how_6599078_replace-sensor-_97-nissan-altima.html
it has instructions on how to replace the knock sensor on a '97 Altima. Most likely, the procedure and the placement of the sensor are similar on your '00 model.

However, I doubt if the knock sensor is the source of your engine stalling problem.
Another possibility is that you have a problem with the Idle Air Control (IAC).
Are you sure that there are no codes relating to the IAC?

Both the MAF code and the Knock Sensor code indicate a potential problem in the circuitry (wiring) for these devices. Have you traced the wires in order to verify that all connections are tight, and the wiring is not damaged?

I have checked the MAF but I’ll look more carefully at the wires. Thanks for the instructions. I’ll take a look and will try to find the KS and its wires this afternoon!

the mechanic found the ks, it was broken but it didn’t make a diff with the new one. It turns out the hose connecting the valve w the intake was broken, he changed for $30 and now the cars runs like new!