{
    "lazyNodes": false,
    "abFitnotesFlag": false,
    "abCrawlReviews": true,
    "productOptionsCookie": false,
    "orderDelayFlag": false,
    "skipSessionCookie": false,
    "covidMessage": false,
    "fullTitleCookie": false,
    "nrLoggerCookie": true,
    "checkoutReviewCookie": false,
    "productOptionSeqCookie": false,
    "maintenanceFlag": false,
    "bufferETACookie": false,
    "multiShippingDiscountFlag": false,
    "newFitmentFlag": false,
    "surveyOptInFlag": true,
    "crossSellFlag": false,
    "skuMappingFlag": false,
    "paySplitCookie": false,
    "callDisableFlag": true,
    "zipPaymentFlag": "c",
    "hassleFreeReturn": true,
    "lifetimeReplacement": true,
    "cpn_off": false
}
2013 Ford C-Max
1
0
Price Match Guarantee
60-Day Returns
Lifetime Replacement
Price Match Guarantee
60-Day Returns
Lifetime Replacement
2013 Ford C-Max

2013 Ford C-Max Oxygen Sensors

Refine by:

Shop Catalog

Showing 1 - 15 of 29 results
Display item:
15
30
45
Sort by:
Before Catalytic Converter Oxygen Sensor, PLUG-IN HYBRID EV-GAS (PHEV), Eng. VIN: U, FI, Naturally Aspirated, B1S1, Sold individually, 5-wire, 4 Cyl 2.0L
DriveWire
Before Catalytic Converter Oxygen Sensor, PLUG-IN HYBRID EV-GAS (PHEV), Eng. VIN: U, FI, Naturally Aspirated, B1S1, Sold individually, 5-wire, 4 Cyl 2.0L
Part Number: REPA960912
Guaranteed to Fit
$56.49
Vehicle Fitment
  • 2013 Ford C-Max Energi SEL 4 Cyl 2.0L PLUG-IN HYBRID EV-GAS (PHEV), Eng. VIN: U, FI, Naturally Aspirated, B1S1
  • 2013 Ford C-Max Hybrid SE 4 Cyl 2.0L FULL HYBRID EV-GAS (FHEV), Eng. VIN: U, FI, Naturally Aspirated, B1S1
  • 2013 Ford C-Max Hybrid SEL 4 Cyl 2.0L FULL HYBRID EV-GAS (FHEV), Eng. VIN: U, FI, Naturally Aspirated, B1S1
Product Details
Location : Before Catalytic ConverterNotes : Wideband sensorType : 5-wireQuantity Sold : Sold individuallyProduct Fit : Direct FitThread Size : M18-1.5 Thread SizeMounting Style : Threaded-in Mounting StyleHex Size : 7/8 in. Hex SizeInterchange Part Number : 25025049Connector Gender : Male ConnectorWarranty : 1-year DriveWire unlimited-mileage warrantyProp 65 Warning :

Warning SymbolWARNING: This product can expose you to chemicals including Lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Returns Policy : 30-Day Return Policy
Before Catalytic Converter Oxygen Sensor, Eng. VIN: U, FI, Naturally Aspirated, ELECTRIC/GAS, Sold individually, 5-wire, 4 Cyl 2.0L, Walker Products Aftermarket Base Sensor - Before Catalytic Converter
Walker Products®
Before Catalytic Converter Oxygen Sensor, Eng. VIN: U, FI, Naturally Aspirated, ELECTRIC/GAS, Sold individually, 5-wire, 4 Cyl 2.0L, Walker Products Aftermarket Base Sensor - Before Catalytic Converter
Part Number: WKP35035046
Guaranteed to Fit
$100.99
Vehicle Fitment
  • 2013 Ford C-Max Energi SEL 4 Cyl 2.0L Eng. VIN: U, FI, Naturally Aspirated, ELECTRIC/GAS
  • 2013 Ford C-Max Hybrid SE 4 Cyl 2.0L Eng. VIN: U, FI, Naturally Aspirated, ELECTRIC/GAS
  • 2013 Ford C-Max Hybrid SEL 4 Cyl 2.0L Eng. VIN: U, FI, Naturally Aspirated, ELECTRIC/GAS
Product Details
Location : Before Catalytic ConverterNotes : Wideband sensorType : 5-wireQuantity Sold : Sold individuallyProduct Fit : Direct FitWire Length : 21.65 in. Wire LengthWarranty : 90-day Walker Products limited warrantyProp 65 Warning :

Warning SymbolWARNING: This product can expose you to chemical which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Series : Walker Products Aftermarket Base Sensor
After Catalytic Converter Oxygen Sensor, Eng. VIN: U, FI, Naturally Aspirated, ELECTRIC/GAS, Sold individually, 4-wire, 4 Cyl 2.0L, Walker Products Aftermarket Base Sensor
Walker Products®
After Catalytic Converter Oxygen Sensor, Eng. VIN: U, FI, Naturally Aspirated, ELECTRIC/GAS, Sold individually, 4-wire, 4 Cyl 2.0L, Walker Products Aftermarket Base Sensor
Part Number: WKP35034410
Guaranteed to Fit
$44.49
Vehicle Fitment
  • 2013 Ford C-Max Hybrid SEL 4 Cyl 2.0L Eng. VIN: U, FI, Naturally Aspirated, ELECTRIC/GAS
  • 2013 Ford C-Max Energi SEL 4 Cyl 2.0L Eng. VIN: U, FI, Naturally Aspirated, ELECTRIC/GAS
  • 2013 Ford C-Max Hybrid SE 4 Cyl 2.0L Eng. VIN: U, FI, Naturally Aspirated, ELECTRIC/GAS
Product Details
Location : After Catalytic ConverterNotes : HeatedType : 4-wireQuantity Sold : Sold individuallyProduct Fit : Direct FitWire Length : 27.56 in. Wire LengthWarranty : 90-day Walker Products limited warrantyProp 65 Warning :

Warning SymbolWARNING: This product can expose you to chemical which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Series : Walker Products Aftermarket Base Sensor
Upper Oxygen Sensor, From 7/8/13, Sold individually, 4-wire, 4 Cyl 2.0L, Motorcraft OE Replacement - Upper
Motorcraft®
Upper Oxygen Sensor, From 7/8/13, Sold individually, 4-wire, 4 Cyl 2.0L, Motorcraft OE Replacement - Upper
Part Number: MIDY1199
Guaranteed to Fit
$98.99
Vehicle Fitment
  • 2013 Ford C-Max Hybrid SEL 4 Cyl 2.0L From 7/8/13
  • 2013 Ford C-Max Energi SEL 4 Cyl 2.0L From 7/8/13
  • 2013 Ford C-Max Hybrid SE 4 Cyl 2.0L From 7/8/13
Product Details
Location : UpperType : 4-wireQuantity Sold : Sold individuallyProduct Fit : Direct FitReplaces OE Number : DS7Z9F472AWarranty : 2-year or unlimited-mile Motorcraft limited warrantyProp 65 Warning :

Warning SymbolWARNING: This product can expose you to chemical which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Series : Motorcraft OE Replacement
Oxygen Sensor, Sold individually,, Motorcraft OE Replacement
Motorcraft®
Oxygen Sensor, Sold individually,, Motorcraft OE Replacement
Part Number: MIDY1203
Guaranteed to Fit
$63.99
Vehicle Fitment
  • 2013 Ford C-Max Hybrid SEL 4 Cyl 2.0L ELECTRIC/GAS
  • 2013 Ford C-Max Energi SEL 4 Cyl 2.0L ELECTRIC/GAS
  • 2013 Ford C-Max Hybrid SE 4 Cyl 2.0L ELECTRIC/GAS
Product Details
Location : LowerQuantity Sold : Sold individuallyProduct Fit : Direct FitProp 65 Warning :

Warning SymbolWARNING: This product can expose you to chemical which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Series : Motorcraft OE Replacement
After Catalytic Converter Oxygen Sensor
Denso®
After Catalytic Converter Oxygen Sensor
Part Number: NP2344578
Guaranteed to Fit
$43.99
Vehicle Fitment
  • 2013 Ford C-Max Hybrid SEL 4 Cyl 2.0L O.E. Quality Replacement Sensor
  • 2013 Ford C-Max Energi SEL 4 Cyl 2.0L O.E. Quality Replacement Sensor
  • 2013 Ford C-Max Hybrid SE 4 Cyl 2.0L O.E. Quality Replacement Sensor
Product Details
Location : After Catalytic Converter
After Catalytic Converter Oxygen Sensor, Sold individually, 4-wire, OE Replacement Series
Bosch®
After Catalytic Converter Oxygen Sensor, Sold individually, 4-wire, OE Replacement Series
Part Number: BS18138
Guaranteed to Fit
$62.49
Vehicle Fitment
  • 2013 Ford C-Max Hybrid SEL 4 Cyl 2.0L
  • 2013 Ford C-Max Energi SEL 4 Cyl 2.0L
  • 2013 Ford C-Max Hybrid SE 4 Cyl 2.0L
Product Details
Location : After Catalytic ConverterType : 4-wireQuantity Sold : Sold individuallyProduct Fit : Direct FitWire Length : 665 in. Wire LengthWarranty : 1-year Bosch limited warrantyProp 65 Warning :

Warning SymbolWARNING: This product can expose you to chemical which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Promotions : CarParts EuroSeries : OE Replacement Series
Before Catalytic Converter Oxygen Sensor, Eng Vin: U, FI, Naturally Aspirated, FULL HYBRID EV-GAS (FHEV), B1S1, Sold individually, 4 Cyl 2.0L - Before Catalytic Converter
Walker Products®
Before Catalytic Converter Oxygen Sensor, Eng Vin: U, FI, Naturally Aspirated, FULL HYBRID EV-GAS (FHEV), B1S1, Sold individually, 4 Cyl 2.0L - Before Catalytic Converter
Part Number: WKP25025163
Guaranteed to Fit
$83.49
Vehicle Fitment
  • 2013 Ford C-Max Energi SEL 4 Cyl 2.0L Eng Vin: U, FI, Naturally Aspirated, PLUG-IN HYBRID EV-GAS (PHEV), B1S1
  • 2013 Ford C-Max Hybrid SE 4 Cyl 2.0L Eng Vin: U, FI, Naturally Aspirated, FULL HYBRID EV-GAS (FHEV), B1S1
  • 2013 Ford C-Max Hybrid SEL 4 Cyl 2.0L Eng Vin: U, FI, Naturally Aspirated, FULL HYBRID EV-GAS (FHEV), B1S1
Product Details
Location : Before Catalytic ConverterQuantity Sold : Sold individuallyProduct Fit : Direct FitWarranty : 90-day Walker Products limited warrantyProp 65 Warning :

Warning SymbolWARNING: This product can expose you to chemical which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Before Catalytic Converter Oxygen Sensor, Eng Vin: U, FI, Naturally Aspirated, FULL HYBRID EV-GAS (FHEV), B1S1, Sold individually, 4 Cyl 2.0L - Before Catalytic Converter
Walker Products®
Before Catalytic Converter Oxygen Sensor, Eng Vin: U, FI, Naturally Aspirated, FULL HYBRID EV-GAS (FHEV), B1S1, Sold individually, 4 Cyl 2.0L - Before Catalytic Converter
Part Number: WKP35035114
Guaranteed to Fit
$84.99
Vehicle Fitment
  • 2013 Ford C-Max Energi SEL 4 Cyl 2.0L Eng Vin: U, FI, Naturally Aspirated, PLUG-IN HYBRID EV-GAS (PHEV), B1S1
  • 2013 Ford C-Max Hybrid SE 4 Cyl 2.0L Eng Vin: U, FI, Naturally Aspirated, FULL HYBRID EV-GAS (FHEV), B1S1
  • 2013 Ford C-Max Hybrid SEL 4 Cyl 2.0L Eng Vin: U, FI, Naturally Aspirated, FULL HYBRID EV-GAS (FHEV), B1S1
Product Details
Location : Before Catalytic ConverterQuantity Sold : Sold individuallyWarranty : 90-day Walker Products limited warrantyProp 65 Warning :

Warning SymbolWARNING: This product can expose you to chemical which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Before Catalytic Converter Oxygen Sensor, PLUG-IN HYBRID EV-GAS (PHEV), Eng. VIN: U, FI, Naturally Aspirated, B1S1, Sold individually, 5-wire, 4 Cyl 2.0L, Walker Products Original Equipment Base Sensor - Before Catalytic Converter
Walker Products®
Before Catalytic Converter Oxygen Sensor, PLUG-IN HYBRID EV-GAS (PHEV), Eng. VIN: U, FI, Naturally Aspirated, B1S1, Sold individually, 5-wire, 4 Cyl 2.0L, Walker Products Original Equipment Base Sensor - Before Catalytic Converter
Part Number: WKP25025049
Guaranteed to Fit
$94.37
Vehicle Fitment
  • 2013 Ford C-Max Energi SEL 4 Cyl 2.0L PLUG-IN HYBRID EV-GAS (PHEV), Eng. VIN: U, FI, Naturally Aspirated, B1S1
  • 2013 Ford C-Max Hybrid SE 4 Cyl 2.0L FULL HYBRID EV-GAS (FHEV), Eng. VIN: U, FI, Naturally Aspirated, B1S1
  • 2013 Ford C-Max Hybrid SEL 4 Cyl 2.0L FULL HYBRID EV-GAS (FHEV), Eng. VIN: U, FI, Naturally Aspirated, B1S1
Product Details
Location : Before Catalytic ConverterNotes : Wideband sensorType : 5-wireQuantity Sold : Sold individuallyProduct Fit : Direct FitWire Length : 21.65 in. Wire LengthInterchange Part Number : REPA960912Warranty : 90-day Walker Products limited warrantyProp 65 Warning :

Warning SymbolWARNING: This product can expose you to chemical which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Series : Walker Products Original Equipment Base Sensor
After Catalytic Converter Oxygen Sensor, B1S2, Sold individually, 4-wire, 4 Cyl 2.0L, Walker Products Original Equipment Base Sensor
Walker Products®
After Catalytic Converter Oxygen Sensor, B1S2, Sold individually, 4-wire, 4 Cyl 2.0L, Walker Products Original Equipment Base Sensor
Part Number: WKP250241059
Guaranteed to Fit
$50.49
Vehicle Fitment
  • 2013 Ford C-Max Hybrid SEL 4 Cyl 2.0L B1S2
  • 2013 Ford C-Max Energi SEL 4 Cyl 2.0L B1S2
  • 2013 Ford C-Max Hybrid SE 4 Cyl 2.0L B1S2
Product Details
Location : After Catalytic ConverterNotes : HeatedType : 4-wireQuantity Sold : Sold individuallyProduct Fit : Direct FitWire Length : 27.56 in. Wire LengthInterchange Part Number : DF96090005Warranty : 90-day Walker Products limited warrantyProp 65 Warning :

Warning SymbolWARNING: This product can expose you to chemical which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Series : Walker Products Original Equipment Base Sensor
Before Catalytic Converter Oxygen Sensor, O.E. Quality Replacement Sensor, Sold individually, 4-wire, 4 Cyl 2.0L - Before Catalytic Converter
Denso®
Before Catalytic Converter Oxygen Sensor, O.E. Quality Replacement Sensor, Sold individually, 4-wire, 4 Cyl 2.0L - Before Catalytic Converter
Part Number: NP2345113
Guaranteed to Fit
$71.49
Vehicle Fitment
  • 2013 Ford C-Max Energi SEL 4 Cyl 2.0L O.E. Quality Replacement Sensor
  • 2013 Ford C-Max Hybrid SE 4 Cyl 2.0L O.E. Quality Replacement Sensor
  • 2013 Ford C-Max Hybrid SEL 4 Cyl 2.0L O.E. Quality Replacement Sensor
Product Details
Location : Before Catalytic ConverterType : 4-wireQuantity Sold : Sold individuallyProduct Fit : Direct FitWire Length : 18.2 in. Wire LengthInterchange Part Number : 15718Warranty : 1-year Denso limited WarrantyProp 65 Warning :

Warning SymbolWARNING: This product can expose you to chemical which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Upstream Oxygen Sensor, Sold individually, 5-wire, 4 Cyl 2.0L, OE Replacement Series - Upstream
Bosch®
Upstream Oxygen Sensor, Sold individually, 5-wire, 4 Cyl 2.0L, OE Replacement Series - Upstream
Part Number: BS17319
Guaranteed to Fit
$71.99
Vehicle Fitment
  • 2013 Ford C-Max Hybrid SE 4 Cyl 2.0L
  • 2013 Ford C-Max Hybrid SEL 4 Cyl 2.0L
  • 2013 Ford C-Max Energi SEL 4 Cyl 2.0L
Product Details
Location : UpstreamNotes : HeatedType : 5-wireQuantity Sold : Sold individuallyProduct Fit : Direct FitWire Length : 13.39 in. Wire LengthMounting Style : Threaded-in Mounting StyleHex Size : 22 mm Hex SizeConnector Gender : Male ConnectorWarranty : 1-year Bosch limited warrantyProp 65 Warning :

Warning SymbolWARNING: This product can expose you to chemical which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Promotions : CarParts EuroSeries : OE Replacement Series
Upper Oxygen Sensor, Before 7/8/13, Sold individually, 4-wire, 4 Cyl 2.0L, Motorcraft OE Replacement - Upper
Motorcraft®
Upper Oxygen Sensor, Before 7/8/13, Sold individually, 4-wire, 4 Cyl 2.0L, Motorcraft OE Replacement - Upper
Part Number: MIDY1183
Guaranteed to Fit
$92.99
Vehicle Fitment
  • 2013 Ford C-Max Hybrid SEL 4 Cyl 2.0L Before 7/8/13
  • 2013 Ford C-Max Hybrid SE 4 Cyl 2.0L Before 7/8/13
  • 2013 Ford C-Max Energi SEL 4 Cyl 2.0L Before 7/8/13
Product Details
Location : UpperNotes : HeatedType : 4-wireQuantity Sold : Sold individuallyProduct Fit : Direct FitReplaces OE Number : BA5Z9F472BWarranty : 2-year or unlimited-mile Motorcraft limited warrantyProp 65 Warning :

Warning SymbolWARNING: This product can expose you to chemical which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Series : Motorcraft OE Replacement
Oxygen Sensor, Sold individually, 5-wire
NTK®
Oxygen Sensor, Sold individually, 5-wire
Part Number: NG24348
Guaranteed to Fit
$84.49
Vehicle Fitment
  • 2013 Ford C-Max Energi SEL 4 Cyl 2.0L
  • 2013 Ford C-Max Hybrid SE 4 Cyl 2.0L
  • 2013 Ford C-Max Hybrid SEL 4 Cyl 2.0L
Product Details
Location : Before Catalytic ConverterNotes : 0.38 in. Thread Length; Heated Sensor TypeType : 5-wireQuantity Sold : Sold individuallyProduct Fit : Direct FitWire Length : 20.8 in. Wire LengthThread Size : 18 mm Thread SizeWarranty : NGK limited warrantyProp 65 Warning :

Warning SymbolWARNING: This product can expose you to chemical which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Page 1 of 2 | Showing 1 - 15 of 29 results

Top Rated Products

DriveWire Before Catalytic Converter, Oxygen Sensor, 5-Wire, Wideband Sensor
$56.49( Review)
The Carparts is an autoParts that sells you what you need, with all the online tools See More
Jose R.
VERIFIED PURCHASER

Popular Products

Product Questions & Answers

Bosch Upstream Oxygen Sensor, Sold individually, 5-wire, 4 Cyl 2.0L, OE Replacement Series - Upstream
$71.99
Q:Do I need to order 2 sensors upstream & 2 sensors downstream.(I drive a 2013 Range Rover Evoque)? Show Less
Quincy13
A:BEST ANSWERHi Tracey, I'm glad to assist you. Since your SUV has a 4-cylinder engine, you only need one upstream and one downstream sensor. The one you have chosen is the upstream, and the one for the downstream sensor is part number BS16256. Grab our lowest offer and click the two links below to buy them today. Happy shopping! https://www.carparts.com/oxygen-sensor/bosch/bs17319?can=cpje1043_CSQA_20240630 (Upstream sensor) https://www.carparts.com/details/Land_Rover/Range_Rover_Evoque/Bosch/Oxygen_Sensor/2013/Dynamic/4_Cyl_2-dot-0L/BS16256.html?can=cpje1043_CSQA_20240630 (Downstream sensor) Show less
Jeonino E.
 
1 Question, 1 AnswerView all Q&As >
NTK Oxygen Sensor, Sold individually, 5-wire
$84.49
Q:Hi does this part fit a 2018 Hyundai Tuscan SEL 4 cylinder 2.0L?
Marcella B.
A:BEST ANSWERHi Marcella, thank you for reaching out. Yes. This product fits the 2018 Hyundai Tucson SEL with a 2.0-liter engine. You can use this link to continue ordering this part at a discounted price today: https://www.carparts.com/oxygen-sensor/ntk/ng24348?can=CPAP3648_CSQA_20241007 I hope this helps. Enjoy shopping. Show less
Aldrin P.
 
4 Questions, 1 AnswerView all Q&As >

Helpful Automotive Resources

P2187 Code: System too Lean at Idle (Bank 1)
P2187 Code: System too Lean at Idle (Bank 1)Note that there is only one bank if your car has a straight engine and the scan tool will always refer to that bank as “Bank 1.” P2187 code indicates that your vehicle’s computer detected a potential issue with the fuel mixture at idle.
P2270 Code: O2 Sensor Signal Biased / Stuck Lean (Bank 1, Sensor 2)
P2270 Code: O2 Sensor Signal Biased / Stuck Lean (Bank 1, Sensor 2)Bank 1 is where the #1 spark plug is. O2 sensor 1/1 is the upstream sensor on Bank 1 (different for a Ford than for a Chevy or a Dodge), and O2 sensor 1/2 is the downstream sensor on Bank 1. O2 2/1 is upstream on Bank 2 and O2
P0141 Code: Oxygen Sensor Heater Circuit Malfunction (Bank 1, Sensor 2)
P0141 Code: Oxygen Sensor Heater Circuit Malfunction (Bank 1, Sensor 2)With that in mind, it’s important to note that Bank 1 is always where the number 1 cylinder is located. Thus, on Ford pickups, Bank 1 is the passenger side bank, but on Chevy and Dodge pickups, Bank 1 is the driver side bank. You need to know this, or
P0042 Code: HO2S Heater Control Circuit Bank 1 Sensor 3
P0042 Code: HO2S Heater Control Circuit Bank 1 Sensor 3Bank 1 is the side of the engine where the #1 cylinder is located. P0042 code is set when your car’s PCM determines a potential problem with the heater element circuit of the oxygen sensor.
P0135 Code: Heated O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)
P0135 Code: Heated O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)Diagnostic trouble code (DTC) P0135 stands for “Oxygen O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1).” It is set when the car’s primary computer—also called the powertrain control module or PCM—determines that the heated oxygen sensor (HO2S) 1 heater current is higher or lower than the ideal amp for
P0134: O2 Sensor Circuit No Activity Detected (Bank 1, Sensor 1)
P0134: O2 Sensor Circuit No Activity Detected (Bank 1, Sensor 1)The Bank 1 portion of the code refers to the side of the engine with the number one cylinder. Sensor 1 refers to the upstream O2 sensor.