03 Lancer 2.0L Check Engine Light on, Bank 1 Sensor 1 problem
 

Check engine light came on in my 03 Lancer.

I took it to Autozone and they told me there was a problem with 'bank 1 sensor 1'. They said that narrowed it down to 3 components. Front o2, front catalytic, or rear 02.

I tried a front o2 and light still on.

I aware there was a recall on this model. I called Mitsu and they said software was updated. Unfortunately mileage to high for warranty.

From what I understand these models are noted for the front catalytic going bad. Mitsubishi Lancer Oz Rally: I recently got a diagnosis on my - JustAnswer

Any one else had any experience with these? Is there a way to verify that it is a catalytic?

Have you tried resetting the code to see if it reappears?

Yes

Unhooked battery for 10-15m.

Light came back on in 20 or so miles.

Just trying to figure out how to check o2 sensor voltages before throwing a cat at it