P0172 2003 Nissan Altima Sedan - tune-up and valve cover replacement?

Question

My New Orleans Cottman Transmissions repair shop found a P0712 error code and recommended a tune-up and possibly replacing the valve cover gasket. A total of $300 - $350 for the job. Is this logical and reasonable for a 2003 Nissan Altima?

Answer 1

p0172 means Fuel Injection System Too Rich Bank 1

its possible if the spark plugs are bad it might cause this, also a dirty or bad mass air flow sensor, or a bad oxygen sensor 

why replace the valve cover? if its leaks around just replace the valve cover gasket gasket is $25 and takes less than 30 min to do. If its leaking inside the spark plug the valve cover will has to be replaced which is less than a $140 dealer from the dealer.  

OEM Spark plugs are about $10 each and less than 30 min to install them.

so 1 hour labor for both things sounds good.

Possible causes

- Faulty front heated oxygen sensor

- Ignition misfiring

- Faulty fuel injectors

- Exhaust gas leaks

- Incorrect fuel pressure 

- Faulty Mass Air Flow (MAF) sensor