Your check engine light came on, and the code reader shows something like P0133 or P0136. The shop says an O2 sensor is bad and hands you a quote. Before you say yes, it helps to know what the part and the labor really cost.
So how much does an O2 sensor replacement cost? About $150 to $600 for one sensor at a shop, by two shops’ own price ranges. The sensor alone is about $30 to $90 from a parts shop, and $157 to $230 from Toyota for a 2018 Camry.
In this guide I will show you what the sensors cost, what shops charge to fit them, what owners were quoted and paid, and when it makes sense to do the job yourself.
Which Sensor Is Bad?
Every exhaust bank has at least one sensor before the catalytic converter and one after it. So a four-cylinder car usually has two, and a V8 like the Challenger further down has four.
The code tells you which one. Mr Automotive Repair, a shop in Gainesville, Georgia, explains that P0131 points to Bank 1, Sensor 1, the front one, and P0136 to Bank 1, Sensor 2, the one behind the converter.
The front sensor costs more. On newer cars it is often an air-fuel ratio sensor, the one that controls the fuel mixture, and you will see the price gap in the list below.
What the Sensors Cost
I checked these prices on October 5, 2026. The Toyota parts are for a 2018 Camry, from ToyotaPartsDeal, a Toyota dealer’s parts website:
So a Toyota sensor bought from a dealer’s website already costs less than its list price. The rear one, 89465-06380, is $160.28 there against Toyota’s list price of $227.86.
What Shops Charge to Fit One
Two shops publish their own prices for this job, with parts and labor included:
- Mr Automotive Repair in Gainesville, Georgia, gives $150 to $400 per sensor.
- Luxury Auto Works, a European car shop in Austin, Texas, gives $300 to $600 for a front sensor on a BMW.
The labor rate is the part that changes most from town to town. Tekmetric, a company that makes software for repair shops, found the average US rate was $132 an hour in June 2026, from $85 in the cheapest state to $197 in the dearest.
What Owners Were Quoted and Paid
Price lists are useful, but real quotes tell you more. These come from Tacoma World and the Dodge Challenger forum, two owners’ forums:
- The owner of a 2012 Challenger R/T with the 5.7 Hemi was quoted $633 to replace two sensors and $900 for all four by a mechanic in Southern California, in December 2023.
- A Toyota dealer quoted the owner of a 2009 Tacoma $240 for two hours of labor to fit a $140 sensor, so $240 + $140 = $380, in July 2017.
- A Tacoma owner bought a Denso front air-fuel ratio sensor for $148 in May 2025, and another member pointed out that the one for a manual gearbox is $180.
- For a 4.0 V6, an owner found a Denso front sensor for $132 and a rear one for $52 on RockAuto, in March 2022.
- Another owner paid $71.78 delivered for a Denso rear sensor in January 2023, at least $30 less than the local stores.
So the part is often well under $100, while a shop quote for the same job runs into hundreds. Ask the shop to split the quote into parts and labor, so you can see which one is high.
Look at the four sensor quote too. The Challenger owner’s $633 for two comes to $316.50 a sensor, and $900 for four comes to $225 a sensor.
Can You Replace It Yourself?
Many owners do. You need a sensor socket, and an old sensor can sit very tight in the pipe. A Tacoma owner advised spraying it with WD-40 the night before.
Check the wire length before you fit the new one. The 2025 Tacoma owner found the new sensor’s wire was only about 10 inches, where the old one was about 21, because it was the version for an automatic.
Do not leave a bad sensor for months. Mr Automotive Repair warns that a failing sensor can damage the catalytic converter, which costs $800 to $2,200 to replace there.
If your state tests emissions, a bad sensor is worth fixing before the test. My smog check cost guide shows what that test costs in California and eight other states.
Questions You Might Still Have
How much does it cost to replace an O2 sensor?
About $150 to $600 for one sensor at a shop. Mr Automotive Repair in Georgia gives $150 to $400, and Luxury Auto Works in Austin gives $300 to $600 for a front sensor on a BMW. The part alone is $29.79 to $89.95 aftermarket.
How much is an oxygen sensor?
The aftermarket sensors above cost $29.79 to $89.95. Toyota’s own sensors for a 2018 Camry cost $156.77 to $229.67 on a dealer’s parts website.
Should I replace all the O2 sensors at the same time?
It can be cheaper per sensor. A Challenger owner was quoted $633 for two sensors, which is $316.50 each, and $900 for all four, which is $225 each.
Can I drive with a bad O2 sensor?
For a short time, but get it fixed. Mr Automotive Repair says a failing sensor can use 20 to 40% more fuel and slowly damage the catalytic converter.
Is the upstream or the downstream sensor more expensive?
Usually the upstream one, before the converter. For a 2018 Camry, Toyota’s air-fuel ratio sensors are $173.15 to $229.67, and its oxygen sensors behind the converter are $156.77 to $160.28.
Where These Prices Come From
- ToyotaPartsDeal, 2018 Toyota Camry oxygen sensors, checked October 5, 2026.
- RockAuto, part search for Denso 234-4260, and 1A Auto, oxygen sensors for the Camry, checked October 5, 2026.
- Mr Automotive Repair, Gainesville, Georgia, O2 Sensor Failure: Symptoms, Which One Is Bad, and Replacement Cost, checked October 5, 2026.
- Luxury Auto Works, Austin, Texas, BMW Check Engine Light Diagnostics, checked October 5, 2026.
- Tekmetric, Average Auto Repair Labor Rates by State, June 30, 2026.
- Dodge Challenger forum, Repair cost: Oxygen 02 Sensor Replacement, 2012 Hemi (December 2023).
- Tacoma World, fair labor charge for a Bank 1 O2 sensor (2017), When to replace O2 sensors? (2022), Downstream oxygen sensor, replace again! (2023) and Air-Fuel sensor issue (2025).
I hope this helps you read your quote with a bit more confidence. If you have any questions about your own car, you can email me at costcheckr@gmail.com.
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