Frequently Asked Questions – O2 Sensor Spacers & Oxygen Sensor Adapters

What is an O2 sensor spacer and why is it used?

An O2 sensor spacer, also called an oxygen sensor adapter or catalytic converter spacer, is a small threaded fitting installed between the O2 sensor and the exhaust pipe. It repositions the sensor slightly out of direct exhaust flow. This helps reduce false check engine lights in vehicles with high-flow or modified catalytic converters, or for diagnostic/off-road use where legal.

Which error codes can an O2 sensor spacer help with?

Our spacers may assist with common diagnostic trouble codes, including:

P0420 – Catalyst System Efficiency Below Threshold (Bank 1)
P0430 – Catalyst System Efficiency Below Threshold (Bank 2)

Note: Results may vary depending on your vehicle and exhaust setup.

Is this product legal for street use?

These spacers are intended for motorsport, and off-road use only where permitted. They are not a substitute for a functioning catalytic converter. Always check and follow your local emissions laws.

Will this spacer fit my vehicle?

Most vehicles use the standard M18 × 1.5 thread size, making our spacers widely compatible. If unsure, check your sensor thread size or consult your mechanic.

How many spacers do I need?

Vehicles with single exhaust usually → 1 spacer.
Vehicles with dual exhaust usually → 2 spacers (one for each bank).

How do I install an O2 sensor spacer?

Locate the downstream O2 sensor (after the catalytic converter).
Remove the sensor from the exhaust bung.
Thread the spacer into the bung.
Reinstall the sensor into the spacer.
Tighten securely with basic hand tools.

Pro tip: Apply anti-seize to threads for easier future removal.

What if my Check Engine Light (CEL) doesn’t clear after installing?

Reset the ECU with an OBD-II scanner or by disconnecting the battery.
Make sure the spacer is on the downstream sensor (not the upstream).
Check the O2 sensor itself — if it’s faulty, the spacer can’t override that.
Confirm correct installation angle and thread fit.

Will this help my car pass emissions testing?

Our spacers are not guaranteed to help vehicles pass emissions inspections. They are intended for diagnostic and use where permitted. Compliance depends on your local regulations, and you should always verify before testing.

What materials are these spacers made from?

CatalyticFixer spacers are crafted from high-grade stainless steel for corrosion resistance and durability. Some models also use a ceramic honeycomb insert to simulate catalytic function.

What are the main benefits of using a spacer?

Helps reduce false CEL codes from modified exhausts.
Can extend O2 sensor lifespan.
Easy bolt-on installation, no welding is required.

Do I need a mechanic to install it?

Not necessarily. Most customers install at home with basic tools (O2 sensor socket or wrench). However, if you’re unsure about your exhaust setup, consult a professional mechanic.