scoober101

Just recently Ive had a CEL come on a couple of times with my 2005 WRX PPP. It would clear if I disconnected the battery but it sometimes comes back, it seems intermittent.

I posted recently about how to find out what fault code it is here - https://www.scoobynet.com/general-te...got-a-cel.html

I got myself an OBD2 ELM327 Bluetooth dongle from eBay and the Torque Android app on my phone. Its coming up with:

P0130 - Powertrain O2 Sensor Circuit (Bank 1, Sensor 1)

What can this fault mean and where is the O2 sensor its referring to?

I thought it may have been the MAF but it appears not as I disconnected the MAF with the car running and it then ran rough and also flagging up the dash CEL light. Rescanning with Torque it picked up: P0102 - Mass or Volume Air Flow Circuit Low Input and P0113 - Intake Air Temperature Circuit High Input. So it dosent look like its the MAF.

The car does have an Induction kit if this may have something to do with it but I recently changed the filter in it so its nice and clean.

Any advice?

scooby_Paul

sounds like its the front 02 sensor, the one before the cat

scoober101

If it is a faulty front O2 Sensor, would this affect performance and make any noticeable differences when driving the car. The car seems ok but I wouldnt know the symptoms if there were any?

RICHARD J

iTrader: (4)

Replace the sensor as it may cause it to run lean. In the early stages you may not notice but it could damage the engine if you're unlucky. Keep it off boost & change the sensor ASAP.

propofol

You should be able to use the app to graph the O2.
Main function of sensor is to keep fuel mix at stochiometric for the cat. It does this by switching from rich to lean. You will see the voltage switching from 0.2 to 0.8 volts (or thereabouts). Frequency of it doing this will increase if you hold the revs around 2k.

scoober101

Cheers guys.

Got a new Denso O2 sensor and installed it, quite an easy job to get to the sensor.

Jack up car, remove front drivers wheel, behind small plastic cover in wheel well and used an O2 sensor socket from a local motor factors. Feed the wire in the engine bay and plug it in! Job done.

And, no more CEL's at the moment. Fingers crossed!

Dignitas

Did the change of the O2-sensor really fix the problem?

Don Clark

Bit of a thread resurrection

and to bring it upto date re: diagnostics

Front A/F sensor in manifold before up pipe

Dignitas

Thanks alot for this paper. Can I perform step 3 without the Subaru Select Monitor?