Frequently Asked Questions

What is the first thing to check when the check engine light comes on in a 2018 Lexus LS 500?

• Check the gas cap: a loose or damaged cap is a common, low-cost cause and can trigger EVAP system codes.
• Note driving symptoms: rough idle, stalling, loss of power or fuel smell help prioritize diagnosis.
• Avoid aggressive driving if you suspect a misfire — that can damage the catalytic converter.
• Bring the vehicle to Nalley Lexus Smyrna quickly so factory-trained technicians can read codes with OEM-grade tools.
• Remember: any warranty-covered repairs must be completed at a certified dealership to preserve coverage and ensure long-term savings.

What does it mean when the check engine light comes on in a 2018 Lexus LS 500?

• It indicates the vehicle’s OBD-II system has detected an emissions, engine, or drivetrain fault and stored a diagnostic code.
• Possible causes range from a loose gas cap, oxygen or mass-air sensors, to ignition misfires or catalytic converter issues.
• Some conditions are minor; others can cause damage or reduce fuel economy if left unaddressed.
• Our dealership uses OEM scanners and factory-trained technicians to identify root causes quickly and accurately.
• We often deliver immediate and long-term savings versus many independent shops through precise diagnostics, genuine parts, and warranty protection.

How much does a check engine light diagnostic cost for a 2018 Lexus LS 500?

• Standard diagnostics generally range from a modest diagnostic fee to being complimentary with approved repairs; specific pricing varies by issue.
• Many repairs uncovered by diagnostic testing have predictable price ranges — from inexpensive sensor replacements to higher-cost repairs like catalytic converters.
• Nalley Lexus Smyrna frequently offers service specials and competitive pricing; our factory-trained technicians and OEM parts can reduce repeat visits and long-term costs.
• Repairs covered under warranty must be performed at a certified dealership to maintain coverage and get the fullest value from your warranty.
• Visit our service specials page for current offers: /specials/service.htm or contact us at Nalley Lexus Smyrna for an estimate.

How long does a check engine light service take?

• Diagnostics typically take 30–90 minutes depending on code complexity and required road testing to reproduce the fault.
• Simple fixes (e.g., gas cap, sensor swaps) can often be completed the same day; complex repairs may require parts ordering and take longer.
• Our dealership manages parts inventory and scheduling to minimize downtime and often completes repairs faster than many independent shops.
• We provide clear timelines and estimates before work begins, and warranty repairs are handled promptly by certified technicians.
• Choosing Nalley Lexus Smyrna means upfront transparency, immediate savings on accurate repairs, and long-term savings from correct fixes the first time.

What is the most common reason for check engine light on a 2018 Lexus LS 500?

• Common causes include oxygen or mass-air sensor failures, ignition misfires, EVAP system leaks, and catalytic converter degradation.
• A loose gas cap is a frequent, low-cost trigger for EVAP codes and is easy to check first.
• Misfires are serious because they can rapidly damage the catalytic converter and increase repair costs if ignored.
• Nalley Lexus Smyrna’s diagnostics pinpoint the exact cause quickly, helping avoid unnecessary part replacements and long-term expense.
• Remember: warranty-covered repairs should be completed at a certified dealership to preserve coverage and maximize savings over time.