Catalytic Converter Cleaner & O2 Sensor Spacer Buying Guide
Choose the right FlowRods exhaust care product for your next job. Our range brings together pour-in catalytic converter cleaners, M18x1.5 O2 sensor spacers and convenient two-part kits. Use this guide to compare the products, choose a pack and get ready for installation or routine care.
Which Exhaust Care Product Should You Choose?
Catalytic Converter Cleaner
Choose a cleaner for pour-in fuel-system and exhaust care. The FlowRods 120ml formula is designed to help reduce carbon buildup and maintain smoother exhaust flow without removing the catalytic converter. It is compatible with gasoline and diesel vehicles.
Shop catalytic converter cleaners and compare bottle packs.
M18x1.5 O2 Sensor Spacers
Choose an O2 sensor spacer when your installation calls for a compatible M18x1.5 adapter. FlowRods spacers combine a solid metal body, integrated mini catalytic honeycomb core and wrench-friendly hex base for a compact, secure connection.
Shop M18x1.5 O2 sensor spacers in 1-, 2-, 3- and 4-piece packs.
Spacer and Cleaner Kits
Choose a kit for hardware and pour-in care in one order. Each kit contains one M18x1.5 O2 sensor spacer and one 120ml catalytic converter cleaner. Select 1, 2 or 4 kits to match your maintenance plan.
How to Use FlowRods 120ml Catalytic Converter Cleaner
- Check the bottle directions and your vehicle manufacturer's guidance before use.
- Pour one full 120ml bottle into up to 30L of fuel, approximately 7.9 US gallons.
- Drive normally and follow your regular maintenance schedule.
- For repeat care, use no more than one bottle per week.
No engine or catalytic converter disassembly is required. See the 120ml cleaner product page for pack choices and full directions.
O2 Sensor Spacer Fitment Checklist
- Thread: confirm M18x1.5 threads at both the sensor and intended exhaust port.
- Position: identify the sensor location where the adapter will be installed.
- Clearance: measure the space around the exhaust port and nearby components.
- Installation: professional installation is recommended; use only where permitted.
Compare spacer options and read the fitment FAQ.
Choose Your Pack Size
Cleaner packs let you plan repeat care or stock up for multiple vehicles. The dedicated 3-pack contains three 120ml bottles (360ml total); the 4-pack contains four 120ml bottles (480ml total). Additional quantities are shown on the main cleaner product page. Spacer packs contain the number of adapters shown in the selected option. Kit quantities refer to complete spacer-and-cleaner sets.
Frequently Asked Questions
How much fuel does one 120ml bottle treat?
One FlowRods 120ml bottle treats up to 30L of fuel, approximately 7.9 US gallons. Follow the bottle directions before use.
Do I need to remove the catalytic converter to use the cleaner?
No. Add the cleaner directly to the fuel tank according to the directions.
What does M18x1.5 mean?
M18x1.5 specifies an 18mm thread diameter with a 1.5mm pitch. Match the sensor and exhaust-port threads, position and clearance before ordering.
Is a cleaner the same as an O2 sensor spacer?
No. A cleaner is a pour-in fuel treatment. An O2 sensor spacer is a mechanical fitting. A FlowRods kit combines both products in one set.
Can I choose a multi-pack?
Yes. Choose the quantity on the product page. Cleaner, spacer and kit quantities are listed separately so you can select the right pack for your job.
Can I return an unused item?
Our policy allows return requests within 30 days of receiving an eligible item. Read the return policy for item condition, exclusions and the approval process.
Ready to Choose Your FlowRods Product?
Shop cleaners, O2 sensor spacers or complete kits. Need help with your selection? Contact FlowRods. Check shipping details before ordering.
Routine maintenance products do not repair physically damaged or failed catalytic converters, oxygen sensors or emissions systems. Follow product directions and applicable requirements.