Audi A3 Emissions - 1.6 8V, BSE engine code

[Ryan12345]

Hi, I have high emissions on my A3, 1.6 petrol. I have done a full scan with my diagnostics and no fault codes are stored. The rear O2 sensor is at a steady 0.7V but the front sensor is around 2V. (Not sure if this is correct for a wideband sensor). Any ideas?? Bad CAT? bad front O2 sensor?

[Steve Q]

The sensors will be cheaper than the cat. I'd start with the sensors and work from there. 

[Ryan12345]

The sensor is actually more expensive than the cat being a wideband sensor! I didn't want to just keep changing parts I don't need to

[cliffcoggin]

What makes you believe that either the sensor or the cat is defective? Have you considered that there might be a fault with the engine?

[Steve Q]

I guess a fault within the air/fuel mixture could cause the issue.