Hi all. I've been monitoring my 2009 Aurion ATX (GSV40) for some time after the fuel consumption degraded from 10-11L/100km to 15-16L/100km in urban condition with half time on highway.
With 150K on odometer.
I recently changed new spark plugs, cleaned MAF sensor, throttle body and the pre-cat oxygen sensor in the front.
I used ODB scanner tool to monitor several sensors
Pre-cat sensor voltage and mixture ratio
Post-cat voltage
Throttle position
The findings are
Both pre-cat sensors stay around 3.3v
Post-cat voltage fluctuate between 0 to 0.8v. I attached the graph below along with throttle position.
From this post https://mechanics.stackexchange.com/questions/50101/02-sensor-displays-constant-3-3-volts-not-a-jagged-waveform-2002-rav4
It appears my post-cat sensor reading may indicate a failed catalysts? There is no check engine light come up.
I'm wondering how likely the cat converter is going to fail?
Some symptoms I can relate to is the car always have strong fume smell when start in the morning, but back to normal after warm up.
Any ideas are appreciated.