Skip the auto shop - Our mechanics make house calls

Q: Failed emissions, says that bank system 1 is too lean. The car had sat for almost a year.

asked by on

The car had sat for almost a complete year and had some problems with the intake manifold but we got it fix and we took it to emissions and it failed because it said that the bank system 1 is too lean. We just got a new knock sensor. We're wondering if it has to do with the IAC valve because it had sat for so long or if there is a vacuum or tube leak going on, so do we need to clean it or just get a whole new mass air flow sensor?

My car has 260000 miles.
My car has an automatic transmission.

A: Hello there, thank you for asking about you...

Hello there, thank you for asking about your 1999 Nissan Altima. You need to fix any vacuum leak where un-metered air is getting in to the intake manifold. The additional air getting into the engine will cause the lean codes.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Will the P0597 code cause the car to fail emissions inspection in North Carolina?

Hi there. The code P0597 is for the thermostat heater control circuit. This means that the thermostat is electronically controlled in your vehicle. To see why this code is on, check the following: A loose or corroded connector on...

Q: Full exhaust system is not hooked up.

Check to see what on your exhaust system is hooked up. If your catalytic converter is hooked up and the pipes are hooked to the engine with good gaskets, then as long as the sensors are working, there is nothing...

Q: How do you use the manual rearview mirror?

Depending on the trim level of your car, you may have a manual or an automatic rearview mirror. If yours has the manual option, here’s how to use it: Adjust the mirror so you can see clearly out the...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.