1998 maxima tested valve it works, but stil have one code 1493

That depends upon what AAmco did. These codes are all over the place and seemingly unrelated. It is possible if they did major work that some of these items may have been disconnected and reconnected for the repair. They should have tested and cleared all codes before returning the vehicle. Some of the codes set, if still present as errors, should render the car inoperable. I would clear the ECM of codes and see what comes back after a period of normal driving use over a few days. Then I would worry about what codes are present, if any.

Dont change things til u no cause. Fuel pump probly bad..car is old. Put key to on position and off three times..then try starting. If it gos then pump is stil good and thers a pressure leak in rail. But again its du as a maintenanc item

I had the same problem with my maxima and the alarm I replaced my starter and haven't had any problems with it yet and my alarm is back and up running as we'll so I would start with your starter.... I took mine to the auto parts store tested great because it decided not to act up at the time....but dead again all the sudden.... took starter out it was shot and put in the new one fires up everytime now alarm works great hope this helps

Code 404 is for a problem with the EGR valve and code 307 is for a miss on cylinder 7.
The egr valve would need to be tested, and the spark plug and injector checked out on cylinder 7.

A code P0300 may mean that one or more of the following has happened:

• Faulty spark plugs or wires
• Faulty coil (pack)
• Faulty oxygen sensor(s)
• Faulty fuel injector(s)
• Burned exhaust valve
• Faulty catalytic converter(s)
• Stuck/blocked EGR valve / passages
• Faulty camshaft position sensor
• Defective compute
• P1105MAP/BARO Pressure Switch Solenoid Valve
• Check and clean the MAP sensor, or replace.
• P1492EVAP Canister Purge Control/Solenoid Valve (Circuit)
• Replacing the purge solenoid will clear code P1492 This should also clear code P0300 as well.
  

The code is for a problem in the circuit for the crank position sensor.
The sensor and circuit would need to be tested with a meter.

Hi there:
This indicates that a part of the EVAP control system is no longer functioning correctly. The EVAP system consists of many parts, including (but not limited to) the gas cap, fuel lines, carbon canister, purge valve, and other hoses. The (EVAP) emission control system prevents the escape of fuel vapors from a vehicle's fuel system. Fuel vapors are routed by hoses to a charcoal canister for storage. Later, when the engine is running a purge control valve opens allowing intake vacuum to siphon the fuel vapors into the engine.



I suggest replacing the gas cap with preferably one from the Nissan dealer, or OEM equivalent, then clear these codes by disconnecting the negative battery cable for about a minute then drive it normally; if the codes come back, this may take a couple of days, you most likely have to have the system tested for leaks.


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HAVE YOU TESTED THE CLUTCH SAFETY SWITCH LOCATED ON THE PEDAL

Its most likely the vent control valve, which is bolted to the canister behind the rear wheel on drivers side. However, the control valve is held on to the canister with 2 bolts, which will most likely brake or at least on of them. In that case you will need the canister also. You can test the control valve by un-plugin it ads supplying 12 V to it. It should click. Is click is heard, that is a good sound. If no clicking is heard, than the valve is stuck and will need to be replaced. Don't forget about the screws that hold it in. You may need the canister if they brake. Let me know what you find.

Replace the oxygen sensors. The check engine light on a 98 maxima lets you know that there is a problem with the emission system.