UPDATE, MAF PROBLEMS. CODE P0100. SCROLL DOWN FOR MORE INFO!!!







Okay, so after a week of my car smelling like gas I took it to AutoZone and got back codes P0171 and P0174, system too lean.

The guy at autozone said it's probably an oxygen sensor.

But online it's telling me it's probably an intake leak, a fuel pressure problem, lack of fuel, the maf going bad, faulty pcv valve or failed fuel injectors.

I haven't really noticed the engine running with problems. It idles good, normal vibrations. I bought techron fuel system cleaner and filled the tank up and it runs a bit better. I'll see what happens. I'm going to try cleaning the maf and throttle body this upcoming week. also, I have no idea how to check for intake or exhaust leaks, any help?

Anything else you guys recommend checking or doing?

Any help will be appreciated! thanks!

 

with the car running spray some brake clean, throttle cleaner, carb cleaner etc around the motor. listen for a rpm rise. sometimes you can find an vacuum leak this way.

 

Here is what the Nissan FSM says could cause the P0171 and/or P0174:

Possible Cause:
Intake air leaks
Heated oxygen sensor 1 (front)
Injectors
Exhaust gas leaks
Incorrect fuel pressure
Lack of fuel
Mass air flow sensor

Because you got both codes at the same time, I wonder if your MAF is the cause. I don't think both O2 sensors would go bad at the same time. Check for leaks before you go spending any money.

 

Found the real culprit today. I got the P0100 code now and the other two are gone. Darn MAF sensor. The only reason I'm still driving is cause I have to get to work. But otherwise, I'll have her parked. When it's at operating temperature and I'm in neutral, It idles good at 700 rpm for about 5 seconds then it goes down too 500 rpm and idles really rough. When taking off, it feels like it's choking and takes a while. And it always feel as if I'm forcing the car. Luckily, I managed to get a brand new OEM sensor with the assembly for $55 shipped. It's part number is 22680-2y001, the one with the green dot on top.

Am I required to reflash the ecu or do an idle relearn? If so what are the steps for the idle relearn on a 2001 max? I know the reflash only the stealership does.

Thanks in advance guys!

 

You don't need to get the ECU reflashed for replacing the maf. And if the idle was ok before these these codes popped up, you won't need to do the idle relearn.