Frequently Asked Questions

What is the most common reason for check engine light on a 2020 Lexus RX 350L?

• Loose or damaged gas cap causing a small evaporative emissions leak; quick to fix and often clears the code after a drive cycle.
• Faulty oxygen sensors or mass airflow sensors that reduce fuel economy and performance if left unaddressed.
• Engine misfires from worn spark plugs or ignition coils — operating with misfires risks catalytic converter damage and higher repair costs.
• Addressing these issues at Nalley Lexus Roswell often costs less than independent shops while delivering factory-trained technicians and OEM parts.
• Remember: warranty repairs must be completed at a certified dealership to remain covered.

What does it mean when the check engine light comes on in a 2020 Lexus RX 350L?

• It signals the vehicle’s onboard diagnostics (OBD-II) has detected a system fault — ranging from minor emissions issues to engine or sensor failures.
• Codes can indicate emissions leaks, sensor failures, misfires, or transmission faults; the exact meaning requires a scan to read stored trouble codes.
• Ignoring the light can lead to reduced fuel efficiency, increased emissions, or progressive engine damage that raises repair costs.
• Our dealership uses factory diagnostic tools to pinpoint faults precisely, protecting long-term value and warranty status.

What is the first thing to check when the check engine light comes on?

• Confirm the gas cap is tight and undamaged — a loose cap is a common, simple cause that you can inspect immediately.
• Note any changes in performance, unusual noises, or loss of power to relay accurate symptoms to technicians.
• Bring the vehicle to Nalley Lexus Roswell for a professional scan; our factory-trained techs use OEM tools to read and interpret codes accurately.
• For warranty protection, remember repairs covered under warranty must be performed by a certified dealership.

How much does a check engine light diagnostic cost for a 2020 Lexus RX 350L?

• Diagnostic fees vary by cause; a basic scan is typically a modest fee and many dealers apply diagnostics toward repair if performed at the same visit.
• Minor fixes like a gas cap or sensor replacement are generally affordable; more complex repairs (catalytic converter, internal engine) cost more but are precisely quoted after diagnosis.
• Nalley Lexus Roswell often costs less than independent shops while providing factory-trained technicians, genuine parts, and documented long-term savings.
• Repairs under warranty must be completed at a certified dealership to keep coverage valid.

How long does a check engine light service take?

• Initial diagnostic scanning typically takes 30–60 minutes, depending on symptoms and code history.
• Simple repairs, such as replacing a sensor or tightening a gas cap, can often be completed the same day.
• More involved repairs — ignition, fuel system, or catalytic converter work — may require parts ordering and can take a day or more.
• Choosing Nalley Lexus Roswell can speed resolution: our parts availability, factory tools, and trained technicians reduce downtime and lower long-term costs compared with uncertain independent support.