Hi my nissan maxima 1997 is having some problems like idle is very low when the engine is warm! then while driving it was ok but when you stop at the intersection or traffic lights the "IDLE drops down again and it wiil go dead when you try to restart sometimes it won't start and u "hear the "SQUEAKING NOISE! tell what do you think the problem was? Arnie

they are correct change the fuel filters

you know what that sounds like it may be.... believe it or not check your trans fluid (car running WARM and in park ) make sure that the fluid is red almost pink like not dark red. Also why not try and change out the spark plugs and air cleaner!

First replace fuel filter and check the air filter. next if it still does it you need to clean the throttle plate using a tooth brush and top engine cleaner, you also need to teat fuel rail pressuer, if this does not fix the problem then the idle set screw needs to be adjusted. Also if you own a timing light check to see if the timing mark is jumping around, these cars tend to lose the distributor drive pin, it's a easy fix but wanted to make you aware of it. Do not adjust the idle valve till you know that that catalytic converter is ok.

Visit the on-line store, know as reliable-store, they have the repair manuals. I'm sure you will get the solution of your problem.
Nissan Maxima Factory Service Repair Manual 1994 2009

Let's try the cheapest fix first. Change the fuel filter out. You'll probably see a brown looking goop in the gas, This is an "ETHANOL" problem. Read up on it. These are all related to so many idle and acceleration problems. Buy a can of SEAFOAM at the parts house. Fill up tank with Premium and add SEAFOAM. Then change filter out before 500 more miles. This should clean out the water and the goop and the carbon build up caused by the ETHANOL. Add a can of SEAFOAM every 3000 mile after that to a full tank of gas. It will keep your emissions,engine, and fuel lines clean. And will keep your car from line freeze up. Good luck.

EGR valve, throttle position sensor or idle air valve should all be checked

P0400 is auxillary emmisions control and P0500 is vehicle speed idle speed control auxiliary inputs.

Sounds more like the Throttle Position Sensor or another sensor is letting the engine RPM's drop too low. When the RPM's are too low, the oil pump is not pumping enough oil.

Is the coolant level down? This can cause a no heat problem. Anything changed or unusual about engine temp, (high, low), or how long it takes to warm up? If coolant level is ok, let me know about engine temp - warm up time.

throttle position sensor,or egr valve,also check your air filter,if this helps please gine me a fix ya vote