No, you don't want to mess with the front O2 sensor! It's critical for correct engine operation. Yes, bank one would be the front O2 sensor & I'd recommend replacing that first, before the CAT or the rear O2 sensor. In addition, I'd recommend getting a factory/OEM replacement for the front sensor. Like I said, that sensor is one you don't want to go cheap on. :icon_eek:
Just for information, the non-fouler spacer is only for the rear O2 sensor. It works by moving the sensor back out of the exhaust flow. I'm thinking once you replace the front O2 sensor, you won't have to worry about this. :wink:
Bobby...
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