The IAT sensor location on a 97 Infiniti QX4 - 2004 Infiniti QX4

Look for a failing Crank sensor and/or the cam position sensor. A diagnostic test will tell you for sure.

The crank sensor is located at the driver side rear of the engine. it is bolted to the transmission bell housing. Here is a diagram of it's location.


Click on link for location diagram. http://ww2.justanswer.com/uploads/baddad1/2012-01-11_220732_capture.png

check some where along the camshaft

check the MAF sensor, after a few years those start to go bad. Throttle body may also need cleaning.

Crankshaft and or camshaft position sensors are marginal. If they go out, you won't runs at all.

shift solonoid b is in the transmission. not a do it
yourself situation. clear the codes and drive , see
if it comes back before you take it in for repair.

also check wiring going to trans. look for broken
wires and wires that are rubbed through

This link shows the location of the SCV, If your motor is different the location should be similiar. http://img510.imageshack.us/img510/5687/vacuumdiagramuh3.jpg

There's a vaccuum line that runs off the SCV to the SCV check switch.

P0442: Have you inspected the lines, charcoal cannister etc? Make sure the fuel cap is tight. The easiest way to check the system is to have someone perform a smoke test. I had a DTC on my car which indicated a EVAP problem, it turned out to be the Fuel tank evaporator Control Solenoid.

located on the bottom side of engine.

looking for crankshaft sensor on 1998 infiniti qx4

maybe thermostat