Subaru P0420

So when I fire up the Genisys, before it brings up the PIDs I'm tracking, it puts up a screen that shows a readiness test. It says Catalyst ---- Ready

Is that what you were referring to, Tyler?

That's it! Your Catalyst monitor has passed at least once, which is good news. Did the scan data show a steady downstream O2 sensor reading?

If you want to be 200% sure about your new cat, you can clear the codes and recheck the monitor status. Should say something like 'Not Ready' or 'Incomplete'. Drive it some more and get the Catalyst to complete again. If it'll complete consistently, you're probably good to go.

The downstream O2 is a LOT flatter when a steady RPM is held. There are some variations but I ran the same PIDs on my 2012 Impreza with 55,000 miles and it's not perfectly flat there either.

I will try the reset and have it do another readiness test soon.

Lookin' good. Like you saw, it'll never be a total flat line.

Does that STFT Bank 1 Sensor 2 PID ever do much? I ask because I'm pretty sure the Snap-On has that same PID under a different name. :silly:

No, STFT B1S2 is the result of me picking the wrong PID. There's one short term and one long term fuel trim on this 4 cylinder.

I'm still very new to the Genisys but I will learn. There are still a lot of youtube videos out there with tips, which I believe I have someone here to thank for showing me.

I also want to compare the RomRaider output to the Genisys. It uses a OBDII to USB cable to connect to a PC. I can then have it save to a csv. When Paul was doing the oxygen storage test in his video he wasn't sure about the amount of time that elapsed from one frame to the next on his scanner. I'm getting 60-70 milliseconds between rows in RomRaider and that data could easily be graphed in Excel. Not sure but that might make for a more accurate graph than the Genisys and I'm only out $15 for the cable. Sadly, it's mainly for Subaru and certain models of BMW.