O2 Sensor Spacer with Mini Catalytic Converter – Fixes P0420 P0430

Stop the Check Engine Light for Good — Without a Trip to the Shop

If your dash is lit up with a P0420 or P0430 code, chances are your catalytic converter’s efficiency reading isn’t matching what your ECU expects — usually after a high-flow cat, an aftermarket exhaust, or a deleted converter. This O2 sensor spacer solves that by giving your rear oxygen sensor a proper reading again, without touching your exhaust setup.

It’s a stainless steel spacer with a genuine mini catalytic converter built right into it. Screw it onto your existing O2 sensor, thread the sensor back into the bung, and you’re done — no welding, no cutting, no rewiring. Most people have it installed in under 10 minutes with nothing more than a wrench.

How It Works

Inside the spacer sits a small honeycomb core coated in palladium, platinum, and rhodium — the same precious metals used in full-size catalytic converters. As exhaust gas passes through, it converts carbon monoxide, hydrocarbons, and NOx into CO2 and water. That gives the downstream O2 sensor a signal close enough to a healthy catalytic converter that the ECU stops flagging a fault.

Fits Almost Any Vehicle

Built with a universal M18 x 1.5mm thread, it fits the O2 sensor bung on roughly 99% of gas vehicles — including common applications across Toyota, Honda, BMW, Audi, VW, Subaru, Nissan, and more, from small 1.6L engines up to 6.3L, turbo or naturally aspirated.

Built to Last

Made from T-304 stainless steel — not the zinc-coated carbon steel or steel-wool-packed spacers you’ll find in cheaper knockoffs. It handles sustained heat up to around 620°F without the coating peeling, flaking, or rusting out after a season or two.

What’s in the Box

• 1x O2 Sensor Spacer with built-in mini catalytic converter

Install Notes

• Install on the rear (downstream) O2 sensor only — behind the catalytic converter. It will not work on the front sensor.
• Dual exhaust or V6/V8 vehicles typically need two spacers, one per bank.
• Confirm your existing O2 sensor is functioning correctly before installing — this fixes catalyst-efficiency codes, not a failing sensor.
• Hand-tighten first, then snug with a wrench. If you hit strong resistance, stop — don’t force it.

Applicable Codes: P0420, P0421, P0422, P0423, P0424, P0430, P0431, P0432, P0433, P0434