Help! - Need a set of eyes - O2 sensor

[shortnugly]

Hi, I'm troubleshooting the dreaded P0420 code on a 2006 Scooby Baja, 2.5L non-turbo. It's my daughter's car and I'm trying to see if it's just an O2 sensor instead of a $1500 new catalytic converter.

Same engine as a 2003 - 2008 Legacy, (and others)

I have a check engine light on. CEL.

My first attempt was to cut the car side connector off to splice-in an aftermarket upstream (pre-cat) O2 sensor. Cleared the code, then drove it for a few hundred miles and the CEL came back on.

I've heard from several folks that I need to get an OEM Subaru O2 sensor because it requires a wider band (sensing?) than the cheaper aftermarkets provide.

Well, I bought an OEM O2 sensor , and because I had to cut the car/harness side connector off, I lost track of which wires go to each position on the connector. Doh!

I would be most grateful if someone with a 2003 2004 2005 2006 2008 2008 Baja or Legacy Outback could snap a photo of your wire color/positions on your connector.

Using the clip as a reference point as the the bottom of the connector.

That would get me straightened out and I can see if it was the O2 sensor after all.
I'd be happy to drive to your location or anywhere in the Reno/Sparks and outlying areas.

From the back of the car side connector, Which color wire is:

Top left
Top right
Bottom left
Bottom right



Attached are some pics of the wires I have coming from the car/harness side:
One Yellow
One Red
One White
One Yellow/Red stripe

Other couple of pics of what the sensor connector looks like with the bottom clip of the connector as a reference point.

Your help would be most graciously appreciated.

Car side colored wires:


OEM sensor connector:

[shortnugly]

Anyone?

just a quick pic of the back of your car side connector please.

[mikenmel08]

Mines a turbo or I would help you out......

[shortnugly]

thanks, I appreciate the thought. Another Baja owner where I work offered but he had a turbo as well.

[Wingzero_ac19x]

I have attached the wiring diagram for the oxygen sensors. Should help.

Baja.png (88.56 KiB) Viewed 11267 times

[shortnugly]

B18 on the diagram shows the correct color wires I have. Assuming the small bump on the top of all the connectors is the clip?

[Wingzero_ac19x]

correct

[Wingzero_ac19x]

Keep in mind the picture of the connector is facing the front where it would plug up, not the back where the wires go into the connector.

[shortnugly]

Understood.

Thank you very much for the help.

I'll wire it in, clear the code and hope for the best.

Worst case scenario is I'll need a new catalytic converter.

At 116,000, I've dumped $400 for brakes when I first bought it, then $1900 for a timing belt, water pump and tune up.

It runs well and should be good for another 80k.

A new stereo is next up

I'll post up the results of the new O2 sensor.

Thanks again.

[Wingzero_ac19x]

Now that I think about it, if I remember correctly, its the rear Ox sensor that you would need to look at for a P0420 code, not the front. I would also make sure there are no exhaust leaks or anything in the system.

[mikenmel08]

If you paid $1900 for a timing belt, water pump,and a tune up you need to be looking for a new mechanic......That is one of the easiest cars on the road to do that job and someone took advantage of you very badly.....

[shortnugly]

Now that I think about it, if I remember correctly, its the rear Ox sensor that you would need to look at for a P0420 code, not the front. I would also make sure there are no exhaust leaks or anything in the system.

Ok, will do.

Thanks

[shortnugly]

If you paid $1900 for a timing belt, water pump,and a tune up you need to be looking for a new mechanic......That is one of the easiest cars on the road to do that job and someone took advantage of you very badly.....

I had a head gasket oil leak as well. My mechanic essentially had to lift/pull the engine and separate it from the tranny. I saw it out.
He knows what he's doing.

[mikenmel08]

Ok, you didn't mention head gaskets....But you don't have to pull the engine to do head gaskets...Some people like to or think they have to but is not necessary....Either way that justifies the price a little better

[Wingzero_ac19x]

Any update?