What maintenance issues can cause the 2022 Highlander to fail emissions?

Toyota Highlander Fourth Generation (2020-present)

Error Codes

medium

Difficulty

medium

Severity

4 min read

641 words

Problem Statement

Learn about common maintenance issues that can cause emissions failures in the 2022 Toyota Highlander, including symptoms, diagnostic steps, and repair instructions.

Affected Component

emissions system

Symptoms

•Check Engine Light (CEL)
•Poor Fuel Economy
•Rough Idling
•Strong Fuel Odor
•Excessive Exhaust Smoke

Diagnostic Steps

1
Check for Diagnostic Trouble Codes (DTCs)
2
Visual Inspection
3
Check the Fuel System
4
Inspect the Evaporative Emission Control System (EVAP)
5
Monitor Engine Performance

Solution

💡 Expert Tip

For complex repairs like this, consider taking photos at each step. This helps if you need to reverse a step or consult with a mechanic. Also, keep all removed parts organized - you may need to reference them during reassembly.

Verification

After completing the repair, verify that the issue has been resolved:

✓Test the affected component to ensure it functions correctly
✓Check for any error codes or warning lights
✓Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

•Follow the manufacturer's recommended maintenance schedule
•Address warning signs early before they develop into major issues
•Use quality parts and fluids recommended for your vehicle
•Keep detailed records of all repairs and maintenance

Tools & Equipment Required

•OBD-II Scanner
•Flashlight
•Basic Hand Tools (screwdriver, ratchet set)
•Fuel Pressure Gauge
•Smoke Machine (for leak testing)
•Scan Tool with Live Data Capability

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Solution

Maintenance Issues Causing Emissions Failures in the 2022 Toyota Highlander

Failing emissions tests can be attributed to a variety of maintenance issues, especially in newer vehicles like the 2022 Toyota Highlander. Below are common symptoms, diagnostic steps, tools required, and repair instructions.

Common Symptoms of Emissions Failures

Check Engine Light (CEL): The check engine light is illuminated on the dashboard.
Poor Fuel Economy: Noticeable decrease in miles per gallon (MPG).
Rough Idling: Engine runs unevenly when idling.
Strong Fuel Odor: Unusual smell of gasoline.
Excessive Exhaust Smoke: Visible smoke coming from the exhaust, especially during acceleration.

Repair Instructions

Address Diagnostic Trouble Codes
- Based on the DTCs retrieved, replace any faulty components (e.g., oxygen sensors, catalytic converter) as indicated by the codes.
Repair or Replace Leaky Components
- Exhaust Leaks: Replace broken exhaust pipes or gaskets.
- Fuel Leaks: Repair fuel lines or replace the fuel filter if clogged.
- EVAP Leaks: Replace any damaged vacuum hoses, the purge valve, or charcoal canister.
Fuel System Maintenance
- Replace Fuel Filter: Follow the service manual for the correct procedure.
- Clean Fuel Injectors: Use a fuel injector cleaner or have them professionally cleaned.
Catalytic Converter Issues
- If the catalytic converter is found to be inefficient, it may need replacement.
- Ensure proper installation and sealing of new parts.
Routine Maintenance
- Perform regular oil changes and use the correct grade of oil.
- Replace air filters and fuel filters as per the maintenance schedule.
- Keep tires properly inflated and replace them as needed to ensure optimal performance.

Final Steps

After repairs, reset the vehicle’s ECU using the OBD-II scanner.
Drive the vehicle for a minimum of 50 miles to allow the ECU to recalibrate and check for any new DTCs.
Re-test the vehicle for emissions after ensuring all repairs are completed.

By following these steps, you can effectively diagnose and repair maintenance issues that may cause emissions failures in the 2022 Toyota Highlander.