How many O2 sensors are on the 2009 Murano - 2009 Nissan Murano S

You should have 4 on the 3.5 V6. Upstream sensors are before the catalytic converter and down stream are after the catalytic converter. Bank #1 is towards the firewall and bank #2 is towards the radiator.

question edited for clarity, maker is Nissan.
Question moved to Model Category.

https://www.google.com/search?q=2009+Nissan+Murano.+Wiring+diagram+O2+sensor+heater+banks

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cam angle sensor left disconnected?

There are two of them, one is on the exhaust manifold under the hood and the other is after the catalytic converter.

51 and 1168 are O2 sensors. Check for vacuum leaks and make sure the hoses are hooked and tight from the air filter box to the throttle body. P0725 is engine speed sensor/ input shaft speed sensor on the transmission.

You have 4,2 in the exhaust manifolds,2 at the cats.

local auto zone or advance has a tool for rent,special socket for o2sensors,unplug it and unscrew with socket,reinstall reverse order.

hi karen,to locate the o2 (lambda probe)sensor, locate the exhaust manifold (its HOT)and follow the pipe down to the first box,(cat).you will find a 2" small "pipe" at right angles to the exhaust pipe with a wire (or 2) emanating from the top.this IS the o2 sensor.(sometimes fitted onto the front of the cat.depending on market(im in England) you only need to remove this sensor and replace it with a new one.(you can do this yourself,its easy.)

Check your coolant levels 1st, on both cars. If you've already changed out the T-stats, then you need to move on to the temp sensors, might be bad, but if your check engine light is on, pull the codes and see where that points you.