Best way to beat an o2 sensor?

[RobbyP]

Ive going to install a test pipe soon and I'm wondering what is the best way to not trigger the CEL for the second o2 sensor. Ive heard of 3 ways, spark plug anti foulers, wiring a resistor into the sensor, or buying an o2 simulator. I know audi/vw seem to be way more picky for about almost everything so if theres any easier or more effective way that would be awesome too.

[acray]

For me the 043 Highflow cat and their particular 02 sensor spacer worked like a charm. Later on, after I no longer needed it on my A4, the spacer found itself fixing a similar CEL problem on an 2000 CR-V.

I'm sure the 043 spacer is specifically tuned for their particular cat, right? Why else would it cost 3x as much an off the shelf anti-fouler? That's actually not a completely sarcastic point though, consider the size (length) of the anti-fouler if you try that route.

I like it as a thing to try first as it's cheap and easy to install/remove. Or even to stack a few short foulers together to try different lengths.

[aluthman]

Just get an O2 spacer. I think Vibrant makes the one I have.