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SKU:
NLT1W00460
Ships for free in 2–4 business days.
2003-2004 Toyota Corolla 1.8L Upstream Downstream O2 Sensors 2-Pack
$68.99
In Stock
$68.99
Sale price
$68.99
Regular price
This two-piece upstream and downstream oxygen-sensor set fits compatible 2003-2004 Toyota Corolla models with the 1.8L four-cylinder engine and crosses to reference 88974123.
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Compatible Models
We do our best to list all compatible models. Although this may be the part you need, your exact model may not appear below.
Compatible equipment / model
- 2003 Toyota Corolla 1.8L L4 with matching federal or California emissions configuration
- 2004 Toyota Corolla 1.8L L4 with matching federal or California emissions configuration
Product Overview
A fuel-trim code, slow sensor response, or catalyst-monitor fault can involve an oxygen sensor, but intake leaks, exhaust leaks, misfires, oil burning, fuel-pressure faults, and a worn converter can produce the same codes. Review live data before replacing both sensors.
The sensor before the catalytic converter guides mixture correction; the sensor after the converter monitors catalyst output. Connectors, wire length, heater circuit, calibration, and exhaust position differ, so do not interchange the two.
Key Features & Performance
- One upstream and one downstream sensor
- For 2003-2004 Corolla 1.8L
- Crosses to catalog reference 88974123
- Heated sensor circuits for matching exhaust system
- New aftermarket two-piece set
Replaces Part Numbers
- 88974123
Common Uses
- Replacing sensors with confirmed heater or response faults
- Servicing both positions after harness or contamination damage
- Restoring fuel-control and catalyst-monitor inputs after root-cause repair
Technical Specifications
- Product Type: Oxygen Sensor Set
- Primary Application: Toyota Corolla 1.8L exhaust sensing system
- Package Quantity: 2 sensors
- Condition: New
- Replacement Type: Aftermarket
- Package Quantity: 2 sensors
- Positions: Upstream and downstream
- Engine: 1.8L L4
- Reference: 88974123
- Emissions: Verify federal / California configuration
Installation & Fitment
- Let the exhaust cool and repair leaks first
- Identify each sensor by connector and wire length
- Use an oxygen-sensor socket and anti-seize only if the manufacturer permits
- Route away from heat, clear codes, and check live response after a drive cycle
Compatibility Notice
Northline Parts does its best to list all known compatible models, but the correct part may fit an application not shown.
Model, production date, serial number, connector, dimensions, installed options, and previous repairs can affect fitment. Compare the original component and reference information before purchase.
Frequently Asked Questions
Q: Will this pair fix a catalyst-efficiency code? A: Not if the catalytic converter or an upstream engine problem is the cause.
Q: Are the two sensors interchangeable? A: No. Their calibration, connector, and lead routing can differ by position.
Q: How do I confirm this is the correct part? A: Match VIN, 1.8L engine, emissions label, upstream/downstream position, connectors, wire lengths, threads, heater resistance, and reference.
Q: Is this supplied by the original equipment manufacturer? A: No. This is a new aftermarket item. Brand, model, and part numbers are used only to identify compatible applications.
Part Summary
keywords: 2003 Corolla oxygen sensor set, Toyota Corolla upstream downstream O2, 88974123 sensor replacement, Corolla P0420 diagnosis parts, 1.8L heated oxygen sensors
Brand names, model numbers, and reference part numbers are used for identification and compatibility purposes only. Verify the original component, dimensions, and application before purchase.