Free collection in Selby, Johannesburg Courier nationwide · live price at checkout Mon–Fri 08:00–16:30 · Sat 08:00–13:30 · Sun closed
084 306 6660
MiniCatsSA O₂ sensor spacers
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Free collection: Unit 1, 14 John Street, Selby, Johannesburg 2001 Mon–Fri 08:00–16:30 · Sat 08:00–13:30 · Sun closed 084 306 6660 [email protected]
Mini catalytic converter O₂ sensor spacer in brushed stainless steel, shown with the ceramic honeycomb catalyst element and the perforated restrictor disc that sit inside it Spacer, catalyst element and restrictor disc
M18 × 1.5 threadThe common oxygen sensor size on most petrol cars
Catalyst element insideCeramic honeycomb plus a seven-hole restrictor disc
58 mm × 16 mmStainless steel, 0.2 kg
30–60 minutes to fit22 mm slotted socket — no welding, no tuning

Overview

A small part that changes what one sensor reports

What it is

A mini catalytic converter O₂ sensor spacer is a 58 mm threaded adapter that moves your downstream oxygen sensor out of the direct exhaust stream, into a chamber holding a miniature catalyst element. The sensor then reads a damped, delayed gas sample, its signal flattens, and the ECU's catalyst efficiency monitor stops setting P0420 or P0430.

Being straight about it: it changes what the sensor reports. It does not repair a catalytic converter and it does not reduce tailpipe emissions. If an exhaust leak, a lazy sensor or a misfire is the real cause, a spacer only hides a different problem.

Usually a good fit when…

  • P0420 or P0430 appeared after a high-flow cat, downpipe or on an ageing catalyst
  • Fuel trims, misfires and the upstream sensor all check out
  • There are no exhaust leaks ahead of the downstream sensor

Not the fix when…

  • There are misfire, fuel-trim or upstream sensor codes too
  • The downstream sensor itself is slow or faulty
  • The cat has been removed entirely — a spacer may not be enough on a full decat
  • You need the vehicle to meet an emissions test
Diagnose a P0420 first
FIG. 1 — WHERE IT FITS
Where the oxygen sensor spacer fits Side view of a car exhaust line, running from the engine and manifold on the left through the downpipe, catalytic converter, mid-pipe and silencer to the tailpipe on the right. The spacer is fitted only at the downstream oxygen sensor position after the catalytic converter, never at the upstream sensor before it, and an inset detail shows the spacer threaded between the exhaust bung and the vehicle's own sensor. Where it fits Side view. Front of the car is at left; exhaust flows left to right. ENGINE Upstream sensor (pre-cat) Never fit it here your sensor (not supplied) the spacer The spacer fits HERE downstream (post-cat) sensor only manifold downpipe catalytic converter mid-pipe silencer tailpipe V6 and V8 engines have two banks and therefore two downstream sensors - they need two spacers. Detail: bung, spacer, your sensor 58 mm bung in pipe spacer your sensor 58 mm: sensor sits out of the gas stream

Swipe to see the whole exhaust

The spacer goes on the downstream sensor only — the one after the catalytic converter. Fitting it to the upstream sensor causes running problems.

Specifications

One size, machined in stainless steel

Made for the M18 × 1.5 oxygen sensor thread. Male thread into the exhaust bung, female thread for your sensor.

Thread
M18 × 1.5
Length
58 mm
Diameter
16 mm
Body
Stainless steel
Weight
0.2 kg
Sensor
Not included

The part

Thread sizeM18 × 1.5 — male into the bung, female for the sensor
Overall length58 mm
Body diameter16 mm
MaterialStainless steel
Weight0.2 kg
InternalsCeramic honeycomb catalyst element and seven-hole restrictor disc
SKUMC-M18-58

Fitting & ordering

Fits onDownstream (post-cat) oxygen sensor only
Fitting tool22 mm (7/8") slotted O₂ sensor socket
TorqueUsually 40–50 Nm — use the figure in your vehicle manual
Fitting time30–60 minutes · Easy to moderate
Oxygen sensorOxygen sensor not included
In the box1 × mini catalytic converter O₂ sensor spacer
PriceR350.00 per spacer
FIG. 2 — EXPLODED VIEW
Mini catalytic converter oxygen sensor spacer, exploded view Exploded assembly drawing of the M18 x 1.5 stainless steel oxygen sensor spacer. It shows the 58 mm body in cross-section with its female bore and male thread, the ceramic honeycomb catalyst element and the seven-hole perforated restrictor disc that sit inside it, and the vehicle's own oxygen sensor, drawn as a dashed ghost because it is not supplied. What is in the box Exploded view — every part supplied, and the one part that is not. = where those parts sit inside the body 58 mm M18 × 1.5 Ceramic honeycomb catalyst sits inside the body chamber Perforated restrictor disc 7 drilled holes meter the gas sample Your existing O2 sensor NOT INCLUDED re-use the one already on your car Female M18 × 1.5 bore your O2 sensor screws in here Stainless steel body, sectioned Male M18 × 1.5 thread screws into the exhaust bung

Swipe to see every part

The spacer body, the ceramic honeycomb catalyst element and the perforated restrictor disc. Your oxygen sensor, drawn dashed, is re-used and not supplied.

What's in the box

Included

  • 1 × mini catalytic converter O₂ sensor spacer
  • Ceramic honeycomb catalyst element
  • Seven-hole restrictor disc

Not included

  • Oxygen sensor — you reuse your own
  • High-temperature anti-seize
  • Tools

Your oxygen sensor is not included. If yours is old or already has its own fault codes, replace it first — a spacer cannot make up for a sensor that has stopped responding.

Installation

Fitted in 30–60 minutes with a sensor socket and a torque wrench

Unscrew the downstream sensor, screw the spacer in, refit the sensor into it, clear the code. Here is the job at a glance — and what tends to catch people out.

Full step-by-step guide
30–60 minutes
Typical time, including lifting the car
Easy to moderate
Difficulty for a home mechanic
22 mm
Slotted O₂ sensor socket
40–50 Nm
Usual sensor torque — check your manual
  1. Find the downstream sensor

    Find the downstream sensor

    The one after the catalytic converter — never the upstream one near the manifold.

  2. Remove it

    Remove it

    Penetrating oil first, then a slotted 22 mm socket so the wire runs through the slot.

  3. Fit the spacer

    Fit the spacer

    Anti-seize on the threads only, start it by hand, then refit your sensor into it.

  4. Clear and drive

    Clear and drive

    Torque both joints, check wire slack, clear the code and complete a drive cycle.

From the workbench

What the job is actually like, and the handful of things that go wrong — so you can get it right first time.

Work on a cold exhaust

Burns are the usual injury on this job, not crushing. The pipe stays hot long after the engine sounds cool. And axle stands, always — a jack is for lifting, not for holding.

Seized sensors need patience

Soak the base in penetrating oil for fifteen minutes or more, then run the engine up to temperature, let it cool and try again. Work steadily: snatching at it is how bungs get pulled out.

Check slack and clearance first

The spacer is 58 mm long, so the sensor ends up further out. Hold it in place before you torque anything: the wire needs slack to its connector, and the body must clear heat shields, subframe and floor.

Anti-seize on threads, never the tip

A thin smear on the spacer and sensor threads makes the next removal easy. On the sensing tip it contaminates the sensor and gives false readings. Wipe your fingers before handling it.

Listen for leaks at idle

Two threaded joints where there was one means two chances to leak. A tick or hiss at the new joint lets fresh air reach the sensor and can keep the code alive — recheck seating and torque.

Clearing the code proves nothing yet

The light goes off straight away, but the catalyst monitor has to re-run. After a day or two of normal driving, rescan: monitor ready with no pending code means the fix held.

What you need

About 15 minutes for the swap itself — allow longer to lift the car safely or free a seized sensor.

  • Slotted 22 mm O₂ sensor socket
  • Ratchet and extension
  • Torque wrench
  • Penetrating oil
  • Wire brush
  • High-temperature anti-seize
  • Trolley jack and axle stands
  • OBD-II code reader

Compatibility

Will it fit my car?

Most petrol cars with a downstream oxygen sensor use the M18 × 1.5 thread this spacer is made for. Four quick checks confirm it.

Run the full fit check Not sure? Send us your sensor part number

  1. The sensor thread is M18 × 1.5

    The common size on most petrol cars. If a 22 mm (7/8") socket fits the sensor hex, it almost always is.

  2. There is 58 mm of clearance

    The spacer is 58 mm long overall and the sensor sits further out. Check it will not touch a heat shield, subframe or the floor.

  3. The wire has slack

    The loom has to reach the extra distance without pulling on the connector.

  4. One spacer per downstream sensor

    Four-cylinder engines normally have one downstream sensor. V6 and V8 engines usually have two, one per bank, and need two spacers.

FIG. 3 — FIT CHECK
Fitment check for the oxygen sensor spacer Four checks to make before ordering: confirm the sensor thread is M18 x 1.5, allow 58 mm of clearance for the spacer's length, make sure the sensor lead still reaches its connector without being pulled tight, and count one spacer for every downstream oxygen sensor - one on an inline four, two on a V6. Will it fit your car? Four quick checks before you order 1 THREAD caliper or thread gauge M18 x 1.5 18 mm diameter, 1.5 mm pitch Measure the thread on your old sensor, or read its part number. 2 CLEARANCE underbody heat shield exhaust pipe swing room 58 mm the spacer’s own length The spacer is 58 mm long: allow the room. Check nothing fouls. 3 WIRE REACH enough slack stretched tight The lead must reach without being pulled tight. 4 HOW MANY cat downstream sensor Inline 4·1 spacer V6·2 spacers One spacer per downstream sensor — fitted after the cat.

Swipe to see all four checks

Thread, clearance, wire slack and how many spacers: the four things to check before you order.

Delivery & collection

Collect free in Selby, or have it couriered

Collection is always free and usually the quickest. Courier delivery is priced live by The Courier Guy for your exact address at checkout.

RecommendedFree

Collect from PGM Recycling

  • Unit 1, 14 John StreetSelby, Johannesburg 2001
  • Collection hours
    Monday – Friday
    08:00 – 16:30
    Saturday
    08:00 – 13:30
    Sunday
    Closed
  • 084 306 6660 — call ahead outside these hours
  • Please bring your order number and ID. Call ahead if you are collecting outside these hours.
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If a live courier price cannot be had for your address, checkout offers free collection instead.

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FAQ

Questions about this part

Straight answers, including the ones that talk you out of buying.

All questions
What thread size is the MiniCat O₂ sensor spacer?

M18 × 1.5, the thread used by most oxygen sensors on petrol cars. If a 22 mm (7/8") socket fits your sensor hex it almost always is, but check your own sensor before ordering — the will-it-fit guide shows how.

Run the fit check
Does the oxygen sensor come with it?

No. You reuse your existing downstream oxygen sensor. The spacer threads into the exhaust bung, and the sensor then threads into the spacer. If your sensor is old or already has its own fault codes, replace it first.

Will this fix a P0420 code?

It addresses the code by changing what the downstream sensor reports, and it resolves many cases. It will not help if you have an exhaust leak, a failing oxygen sensor or a misfire — rule those out first. It does not repair a catalytic converter and it does not reduce emissions.

Diagnose a P0420 first
Do I need one or two?

One per downstream oxygen sensor. Four-cylinder engines normally have one. V6 and V8 engines usually have two, one per bank, and need two spacers.

How much is delivery, and can I collect?

Collection is free from PGM Recycling, Unit 1, 14 John Street, Selby, Johannesburg 2001 (Mon–Fri 08:00–16:30 · Sat 08:00–13:30 · Sun closed). Courier delivery is priced live by The Courier Guy for your exact address at checkout, and that live price is the only delivery charge. If no live price can be had for your address, checkout offers free collection instead. Orders ship from Johannesburg, Gauteng.

Delivery and returns in full
How long does it take to fit?

Plan on 30–60 minutes. About 15 minutes for the swap itself — allow longer to lift the car safely or free a seized sensor. You need a 22 mm (7/8") slotted O₂ sensor socket, high-temperature anti-seize and a torque wrench.

Read the installation guide
Can it go on the upstream oxygen sensor?

No. The upstream sensor controls fuelling, and slowing its signal makes the engine run badly and sets new fuel trim codes. The spacer goes on the downstream (post-cat) sensor only.

How do I pay?

Checkout runs through PayFast, so you can pay by card or instant EFT. Guest checkout is available — you do not need an account to order.

Will it help my car pass an emissions or roadworthy test?

No. The spacer changes what the downstream sensor reports; it does not reduce what comes out of the tailpipe. It is sold for motorsport, off-road and diagnostic use, and it is up to you to confirm what is permitted for your vehicle.

Reviews

Customer reviews

No customer reviews yet

Reviews are published here once they have been checked. Until then, the fit check and the questions above cover what most buyers want to know.

Will it fit my car? Ask us a question

Legal notice. This part alters how your vehicle reports downstream oxygen sensor readings. Removing or bypassing a functioning catalytic converter on a road-going vehicle may affect its roadworthy status and emissions compliance in South Africa. Sold for motorsport, off-road and diagnostic use. It is the buyer's responsibility to confirm what is permitted for their vehicle and use case.

Ready to clear that catalyst code?

R350.00 per spacer, oxygen sensor not included. Collect free in Selby or courier nationwide, live price at checkout — pay by card or instant EFT.

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R350.00 In stock · sensor not included