Description
The R1234yf O2 sensor that gets your recovery machine running again
When a 1234yf recovery, recycling & recharging machine throws an “O2 Sensor Expired” or “Oxygen Sensor Error,” it stops recovering and charging until the sensor is replaced. This USA-made SW250 oxygen sensor is a direct, OEM-grade replacement for the Neutronics sensor element that Robinair, Mahle/RTI, Mastercool and CPS all rely on — so you clear the fault and get back to work for a fraction of the branded-box price.
The oxygen sensor is the gatekeeper of refrigerant purity
Every modern R1234yf service unit has a built-in refrigerant identifier, and that identifier uses an electrochemical oxygen sensor to measure air content and confirm the refrigerant is clean before it enters your storage tank. This protects you from cross-contamination — but the sensor is a consumable with a finite life.
As it ages, the machine shows an “O2 Sensor Warning,” “Expired,” or “Oxygen Sensor Error” and disables recovery and charging so contaminated refrigerant can’t reach the tank. A fresh sensor clears the fault immediately and restores full operation — keeping your unit within the recovery-efficiency standard it was certified to under SAE J2843.
OEM performance, without the OEM markup
Direct OEM fit
Precision replacement for the Neutronics sensor element found inside major-brand 1234yf machines and identifiers — no adapters, no guesswork.
Clears the error
Resolves “Expired O2 Sensor” and “Oxygen Sensor Error” codes that lock recovery stations, so the unit returns to normal operation.
Made in the USA
Built to high industrial standards for consistent accuracy in refrigerant analysis, run after run.
Skip brand markups
The same physical sensor element the branded boxes use — at a fraction of the automotive-tool-brand price.
Protects your tank
Accurate air/purity readings keep contaminated or cross-mixed refrigerant out of your internal storage.
Easy bench swap
A straightforward screw-in replacement with common hand tools — no calibration and no special equipment required.
Replaces these OEM oxygen-sensor part numbers
All major brands re-box the same Neutronics/Bacharach sensor element. If your machine calls for any of the numbers below, the SW250 is your replacement.
| Brand | OEM part number(s) |
|---|---|
| Robinair | 16916 |
| Mahle / RTI | 022-80174-00 (0228017400) · 360-83241-00 |
| Mastercool | 69HVAC-YFAS |
| CPS Products | RIXOS |
| Neutronics / Bacharach | 1-16-1013-00-2 (NEU-1161013002) — base OEM element |
| Air Components | SW250 (this product) |
Fits dozens of R1234yf machines and identifiers
Robinair
AC1234-4, AC1234-4SL, AC1234-4-230, AC1234-6, AC1234-9 — plus 16990 and 16995 standalone refrigerant identifiers.
Mahle / RTI ArcticPRO
ACX2280, ACX2250, ACX11280, and the ACX22XX and ACX12XX series machines.
Mastercool
Commander 4000 and Commander 4100 units.
CPS Products
FX3030 and FX-Series units using the integrated EID analyzer.
Neutronics / Bacharach analyzer modules
Fits standalone and integrated identifier modules: EID-1234yf-SAE (7-08-1234-02-2), EID-1234yf/134a-SAE (7-08-1234-26-1), and EID-134a (7-08-1000-70-0).
Check your identifier first. This sensor fits Neutronics / Bacharach-based identifiers only — it is not compatible with IDX identifiers. Confirm which module your machine uses before ordering. If your list model isn’t shown, contact us with your machine model and we’ll confirm fitment.
How to replace the oxygen sensor
These steps cover the Robinair AC1234 series; Mahle, Mastercool and CPS units are very similar because the internal Neutronics module works the same way. You’ll need a flathead screwdriver and a socket or driver for the housing.
Open the machine
Power down. Remove the outer cover bolts, slide the cover off, and set the drain tank aside to reach the top racking.
Pull the module
Unplug the harnesses (note positions), remove the two bracket screws, pull the inline filter, and lift the identifier module to a bench.
Swap the sensor
Open the module cover, unplug the white connector, unscrew the old sensor counter-clockwise, then hand-thread the new one in gently — don’t strip the plastic threads.
Reassemble
Reconnect the sensor plug and cover. Remount the module, refit the inline filter with its flow arrow correct (replace if dark/yellow), reconnect harnesses, refit the cover.
Power up & test
Reconnect power, let the machine boot and run its self-checks, and confirm the error has cleared on the display.
Tip: Replace the identifier’s inline filter at the same time if it looks dark or yellow, and never overtighten the sensor — snug is enough to seal the plastic threads.
Technical details
R1234yf oxygen sensor FAQ
Why is my machine showing “O2 Sensor Expired” or “Oxygen Sensor Error”?
How long does an R1234yf oxygen sensor last?
Does this fit Mahle, Mastercool and CPS machines, not just Robinair?
Will it work with IDX identifiers?
Do I need to replace the inline filter too?
Is any calibration or special tool required?
Order the SW250 R1234yf oxygen sensor
USA-made, OEM-grade, and ready to clear that expired-sensor lockout. Not sure it fits your model? Send us your machine and identifier details and we’ll confirm before you buy.
Add to cart ↑ Confirm my fitmentBrand names, machine models and OEM part numbers are used for identification and cross-reference purposes only, and are trademarks of their respective owners. The SW250 is an OEM-grade replacement and is not sold as a branded OEM part. Always confirm your identifier type (Neutronics/Bacharach, not IDX) and follow your machine’s owner’s manual when servicing.
