Skip the auto shop - Our mechanics make house calls

Q: O2 sensor on exhaust manifold...is it upstream or downstream...09 Nissan Altima

asked by on

Service Engine Soon light is on and I am getting the Catalytic converter replaced. I just need to know which O2 sensor to buy ? Upstream or downstream ?

My car has 21400 miles.
My car has an automatic transmission.

Hey there, thanks for writing in about your 2009 Nissan Altima. The downstream O2 sensor is the sensor used for catalyst efficiency. It is not the one in the manifold but the one after the converter. If you need help with an oxygen sensor replacement, our technicians can come to your location to install the correct the part.

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
  • Home
  • Questions
  • O2 sensor on exhaust manifold...is it upstream or downstream...09 Nissan Altima

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: How do I know if I need a stabilizer bar in my 2010 Nissan Murano

Hello. If the vehicle has not been in an accident or has not had any serious suspension damage then you should not need a stabilizer bar. It is rare to need the bar itself. The bar is mounted to the...

Q: EPC doesn't turn off

Hello. The EPC (electronic power control) can cause your vehicle to go into what most technicians call a "creep mode." What it's doing is limiting the amount of throttle that can be applied to the engine in order not cause...

Q: I add antifreeze coolant to my 2005 nissan altima radiator everyday, I only see few drips underneath it

Engine coolant can leak externally through a hose, radiator, water pump, etc. External leaks are typically found by simple pressure testing of the cooling system. To find the leak that exists in your case, and get the required repair estimated,...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
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.