Which Option Should I Choose?
- M18x1.5 lambda/O2 port: choose this plug if your exhaust boss uses the common M18x1.5 sensor thread.
- Aftermarket exhausts: use this to block an unused sensor port on a downpipe, decat, test pipe, manifold or custom exhaust section.
- Unsure thread size: measure the existing sensor thread or check the exhaust manufacturer’s specifications before ordering.
Why Should You Use The Exoracing O2 Sensor Plug?
Many OEM and aftermarket exhaust systems have one or more lambda sensor ports. If one of those ports is not being used, it needs to be sealed properly to stop exhaust leaks, noise, false readings and unwanted fumes.
The Exoracing O2 sensor plug gives you a clean, removable way to block an unused M18x1.5 lambda port without welding the boss shut.
Because it is CNC machined from 304 stainless steel, it is suitable for harsh exhaust environments where heat, moisture and corrosion are common problems.
This is a useful add-on for road, track, turbo, wideband, decat, custom exhaust and fabrication jobs where you need to blank off an unused O2 sensor port properly.
Purchase Includes:
- 1 x Exoracing O2 Sensor Plug M18x1.5 304 Stainless Steel
- 1 x Exoracing Lifetime Warranty
Features:
- Blocks off unused lambda and O2 sensor ports
- M18x1.5 thread suits many universal lambda sensor bosses
- CNC machined from 304 stainless steel
- Removable design allows the sensor port to be reused later
- 19mm hex head works with a common socket size
- Useful for aftermarket exhausts, decats, downpipes, test pipes and custom fabrication
- Helps prevent exhaust leaks from unused sensor ports
- Includes Exoracing lifetime warranty
Exoracing O2 Sensor Plug M18x1.5 Installation Guide:
This is a simple threaded installation, but the exhaust must be cold before fitting.
- Allow the exhaust system to cool fully before starting work.
- Confirm the lambda/O2 sensor boss uses an M18x1.5 thread.
- Check that the port threads are clean and free from damage.
- Screw the O2 sensor plug into the boss by hand first to avoid cross-threading.
- Use a 19mm socket to tighten the plug.
- Torque to 40 to 60Nm where access allows.
- Start the vehicle and check the area for exhaust leaks once fitted.
Installation difficulty: simple service item, but professional installation is recommended if access is difficult or the exhaust threads are damaged.
Reason to buy now: fit this while the exhaust, downpipe, decat or manifold is already off the car, as access is usually much easier.
Technical Specifications:
| Specification | Details |
| Product Type | O2 sensor plug/lambda sensor blanking plug |
| Material | 304 stainless steel |
| Thread Size | M18x1.5 |
| Length | 20mm |
| Width | 22mm |
| Weight | 40g |
| Socket Size | 19mm |
| Torque Setting | 40 to 60Nm |
| Application | Unused M18x1.5 lambda/O2 sensor ports |
| Warranty | Exoracing Lifetime Warranty |
Recommended With This Product:
- Exoracing O2 Lambda Sensor Bung M18x1.5 304 Stainless Steel if you need to add a new lambda sensor port to an exhaust system.
- Exoracing Titanium Exhaust Wrap if the exhaust section is already removed, and you want to reduce radiant heat.
- Exoracing Stainless Steel Cable Ties if you are fitting exhaust wrap at the same time.
Frequently Asked Questions
What does this O2 sensor plug do?
It blocks off an unused lambda or O2 sensor port in an exhaust system, helping seal the port and prevent exhaust leaks.
What thread size is this plug?
This plug uses an M18x1.5 thread, which is commonly used for narrowband and wideband lambda sensor ports.
Will this fit my exhaust?
It will fit if your exhaust sensor boss is M18x1.5. Always confirm the thread before ordering, especially on custom exhausts or imported exhaust systems.
Can I remove it later?
Yes. Because this is a threaded plug, it can be removed later if you need to install a lambda sensor or a wideband sensor into the port.
What socket size do I need?
The plug uses a 19mm socket.
What torque should I use?
Torque to 40 to 60Nm where access allows. Do not force the plug if the threads are damaged or dirty.
Should I use this in a stainless steel boss?
Ideally, this stainless steel O2 sensor plug should be used in a stainless steel boss for best long-term compatibility.
Notes:
- Designed for M18x1.5 lambda/O2 sensor ports only.
- Confirm the boss's thread before ordering.
- Install by hand first to avoid cross-threading.
- Use on a cold exhaust only.
- Torque to 40 to 60Nm where access allows.
- Ideally used with a stainless steel boss.
- Professional installation is always recommended.
- Material:
- Stainless Steel
- Colour:
- Silver
- thread:
- M18x1.5
- Type:
- O2 Sensor Plug
- Category:
- Exhaust System
- card_function:
- SEALS
- card_tagline:
- Blocks unused M18x1.5 lambda ports
- pdp_purchase_help_html:
- Blocks unused lambda ports
- M18x1.5 304 stainless steel
- 19mm head + lifetime warranty
Fitment: check your exhaust boss is M18x1.5.
Exoracing Ltd offers a lifetime warranty against manufacturing defects on this Exoracing Ltd product for peace of mind and a risk-free buying experience! We have 100% faith in our products and know they are of the highest quality, so where most manufacturers offer a year, we decided to offer a massive lifetime warranty.
Exoracing Ltd lifetime warranty will cover repairing, replacing, or store credit to the same purchase value if the part has since been discontinued, at our discretion, for any Exoracing Ltd product that is found defective.
Exoracing Ltd's lifetime warranty policy will only apply if the product was purchased through ourselves or an officially licenced distributor in our network.
This warranty policy is non-transferable and all claims under this policy must be accompanied by the original receipt of sale.