P0122 2007 Nissan Maxima -

Question

My car the engine is 1500 rpm without load , how can decreese the engine rpm to 750 rpm.

Answer 1

P0128 the thermostat most likely need to be replaced if there are no coolant leaks or the level is not low. If the RPM's are high the car is probably in fail safe mode, do the repair and reset the code. 

 

Nissan cars that has the U1000 the first thing to do is lossen all the ground connecters clean them with sand paper on the connector and body and retighen the bolts back 

There will be a few by the engine bay and will look like this lossen all the ground connecters clean them with sand paper on the connector and body and retighen the bolts back 

 

here is the service bulletin from nissan 

https://www.autocodes.com/uploads/nissan/NTB06-009a.pdf

You can also add a grounding kit to help the factory grounds since the factory grounds are thin and can lose connecting since you can rust and or have corrosion.