CelClear™ O2 Sensor Spacer — Stop the Check Engine Light Without Removing the Cat
CelClear™ O2 Sensor Spacer — Stop the Check Engine Light Without Removing the Cat
High Quality
FREE US Shipping
Hassle Free Returns
Couldn't load pickup availability
Eliminate That P0420 Check Engine Light Without Swapping Out Your Catalytic Converter
CelClear™ is the M18*1.5 O2 sensor spacer trusted by mechanics to silence a stuck check engine light without tearing out or replacing the cat. It threads in with a single wrench in under five minutes, moves the downstream sensor away from direct exhaust flow, and delivers the reading your ECU expects. Genuine 304 stainless steel. Compatible with 99% of cars, SUVs, and sports cars that have a standard M18*1.5 sensor port.
Stop Throwing $1,800 at a Check Engine Light That Won't Stay Off
You cleared the code via OBD2, but it popped up again after 50 miles. Dealer wants $1,800 to replace a catalytic converter in a car that runs perfectly. The spark plug non-fouler from the parts store didn’t even fit — wrong thread size. Inspection is two weeks away, and your low-cost options are running out.
➤ Removes the O2 Sensor from Direct Exhaust Flow: The precision-cast filter sits between the sensor tip and exhaust stream, so the sensor measures diluted, post-catalyst gas instead of raw exhaust. Your ECU sees expected readings, and P0420 stays cleared.
➤ M18*1.5 Universal Thread Fits 99% of Vehicles: The standard downstream O2 sensor thread found on Audi, BMW, Subaru, Honda, Toyota, Ford, VW, Land Rover, and many more. If your car uses an M18*1.5 port, this installs perfectly—no adapters, no thread tape play.
➤ 304 Stainless Steel Endures 700°C Without Deforming: Rated -40°C to 700°C, corrosion-resistant and rustproof. Handles daily driving, cold starts, summer heat, and aggressive acceleration. Cheap zinc spacers melt or strip threads—this one won’t.
The Mini-Cat Insert That Tells Your ECU All Is Well
Your ECU compares upstream and downstream O2 sensor readings. The catalytic converter should clean exhaust gas between them—if it can’t (due to aging, removal, or a high-flow downpipe), the downstream sensor sees overly rich gas and triggers P0420. CelClear™ threads in between the sensor and exhaust port with a precision-cast filter that traps a small pocket of post-cat-like gas at the sensor tip.
Spark plug non-foulers attempt similar results with a hollow tube and incorrect threads. They usually miss the mark on newer vehicles and don’t shift the sensor far enough from the flow. CelClear™ is engineered to the actual M18*1.5 spec your vehicle uses, featuring a real filter element designed to dilute gas readings exactly as your ECU expects.
Why DIY Mechanics and Weekend Wrenches Trust CelClear™ in Their Toolbox
If you’ve browsed car forums for an affordable fix, you’ve seen the spacer solution recommended time and again. CelClear™ is the premium version—accurate M18*1.5 threads, genuine stainless steel, and a filter insert that truly works. "Drove three weeks with CEL on after my downpipe install. Threaded CelClear™ in, drove 80 miles, light’s gone. Hasn’t returned in four months." — Marcus T.
Pass Your Inspection, Save $1,800, and Clear That Light Tonight
✓ Pass Inspection Without Replacing the Catalytic Converter: Most state tests just verify the CEL is off and no codes are stored. Kill the light, complete the readiness cycle, pass with ease.
✓ Five-Minute Install with a Single 22mm Wrench: One wrench, a bit of warm exhaust, and you’re done—no welding, no tuning, no shop visit, no lift required.
✓ Built to Withstand Heat, Cold, and Aggressive Driving: Made of 304 stainless rated to 700°C, able to handle city heat soak, cold winter starts, and spirited runs without warping or rusting out.
3-Step Installation — One Wrench, Five Minutes
Step 1: Use a 22mm wrench to unscrew your downstream O2 sensor. Wait until exhaust is warm but not hot for cleaner threads.
Step 2: Thread CelClear™ directly into the vacant O2 bung. Tighten by hand first, then secure firmly with the wrench.
Step 3: Screw your O2 sensor back into CelClear™’s top. Start the engine, drive 50–80 miles to clear the code. CEL disappears.
| CelClear™ | Spark Plug Non-Fouler | New Catalytic Converter |
|---|---|---|
| M18*1.5 thread—fits 99% of vehicles | ❌ 18mm spark plug thread, incorrect size for most cars | ❌ Replaces a part that’s still functional |
| Filter element correctly dilutes sensor readings | ❌ Hollow tube, typically fails to clear the code | ✅ Effective but costs $800–$2,000 installed |
| 304 stainless steel rated to 700°C | ❌ Zinc or aluminum that can melt or strip threads | ✅ OEM-grade material used |
| Installs in 5 minutes with one wrench | ❌ Quick install but unreliable on newer models | ❌ Hours of labor plus shop fees |
Complete Specs for the Detail-Oriented
- Thread: M18 x 1.5mm — standard downstream O2 sensor thread
- Material: 304 stainless steel body with precision-cast filter insert
- Temperature range: -40°C to 700°C (-40°F to 1292°F)
- Included: 1x CelClear™ adapter body, 1x filter element
- Compatibility: 99% of cars with M18 x 1.5 O2 sensor ports — Audi, BMW, Subaru, Honda, Toyota, Ford, VW, Land Rover, and most others
Got Questions? Here’s What You Should Know
Will it fit my vehicle?
If your downstream O2 sensor uses an M18 x 1.5 thread—which covers about 99% of cars built after 2000—the answer is yes. Remove the sensor to check the threads, or consult a sensor cross-reference for your model. Spark plug non-foulers (18mm) won’t fit; this is the precise size you need.
Is it truly 304 stainless or just cheap metal?
Genuine 304 stainless steel. A magnet won’t hold tight to it. Rated from -40°C up to 700°C, corrosion-proof and rust-resistant. The same grade used in proper exhaust components.
Will the check engine light come back?
Once the code clears—typically after 50–80 miles of combined driving post-install—the light stays off in most cases. Some cars require a longer drive cycle to mark readiness—just be patient and drive normally. If your issue lies beyond O2 sensor readings (like misfire or EVAP), that will need separate attention.
What if I drive aggressively or take the car to the track?
700°C exceeds the heat normally seen at the downstream O2 sensor port, even during hard pulls. We chose 304 stainless specifically so this spacer won’t be the weak point.
What if it doesn’t work on my car?
Contact us, and we’ll make it right—refund or replacement until you’re satisfied. See our guarantee below.
If CelClear™ Doesn’t Extinguish the Light, We’ll Fix It
Install CelClear™, complete your drive cycle, and if the check engine light persists, get in touch. We’ll collaborate on a refund or replacement until it’s resolved. Our purpose is a low-cost fix that actually works—and we stand behind it.
Rated 4.7 / 5 based on 1289 reviews. Showing our 5-star reviews.