Check Enline Light - Fault code P0171

[osmononame]

Hi, my car started to idle roughly a few weeks back - no CEL.

 

I took it to my garage and they said it was an o2 sensor - upstream and downstream. Their supplier was out of stock so i sourced them myself and had them fitted by the garage.

 

I picked the car up yesterday and the revs were hunting for a bit - i just put it down to it not being driven for a few weeks/low battery etc etc but today the CEL came on - it didn't come on before. The car is still idling roughly.

 

I plugged it into my bluetooth fault code reader and it came up with the above error. Searching online it could be a myriad of things - has anyone had a similar problem and if so whats likely to be the cause?

[Sam Mcgoo]

P0171 Fuel System Lean, Bank 1

 

The O2 sensors have different codes to that. But a faulty sensor could possibly give that indication. Running lean, isn't a good thing so Don't drive hard until this is sorted as detonation could occur and cause damage.

 

If it was me, I would jack the car up, disconnect and swap the two front O2 sensors over, the ones nearest the engine. (The rear sensors shouldn't influence this fault)

Take the one from the passenger side and put it in the drivers side and vise verse then re-connect in the new position.

Reset the error codes and try again. If it still says 'bank 1' and not 'Bank 2' then you know its not the sensors.

 

If it still shows the fault, it could be as simple as an exhaust leak before the sensor on the manifold sucking in some air, or more serious like a fueling problem on bank one such as a dirty or sticky injector.

 

Let us know how you get on.

Edited March 29, 2013 by Sam Mcgoo

[osmononame]

Hi guys,

 

Only got round to looking at this issue recently (car has been parked up). I checked with the garage about the o2 sensor they replaced last time and they replaced only the downstream one. The upstream one I got them apparently was the wrong one so they didnt replace it (I found it in the boot afterwards).They said I needed a right front one - so i checked the NGK website and ordered one with the correct part number and dropped the car off again. I have just had a call saying that the sensor they require to replace has 6 wires and the one i supplied was 4 wires. But heres the thing - all the o2 sensors for the 350z on the NGK website have 4 wires. I have also checked the Bosch website and they are all 4 wires as well.

 

So can anyone confirm whether the 350z has 6 wire o2 sensors or 4 wire?