Frequently Asked Questions

What is the most common reason for check engine light on a 2018 Lexus RC 300?

• Common causes include misfires (P0300–P0304), oxygen sensor faults (P0135), catalytic converter efficiency (P0420) and fuel trim issues (P0171/P0174).
• Left unaddressed, misfires and bad O2 sensors can lead to catalytic converter failure — a far costlier repair than the initial fix.
• Nalley Lexus Smyrna’s factory-trained technicians quickly pinpoint the root cause using OEM tools, often costing less upfront and saving you money long term compared with independent shops.
• Remember: repairs covered under warranty must be completed at a certified dealership to preserve coverage and ensure correct parts and procedures.

What does it mean when the check engine light comes on in a 2018 Lexus RC 300?

• The light signals the vehicle’s onboard diagnostics detected an issue — from minor sensor faults to engine misfires or emissions problems.
• It does not always mean immediate danger, but it does mean further diagnostics are needed to prevent escalation and higher repair costs.
• At Nalley Lexus Smyrna we use OEM scanners and manufacturer procedures to provide accurate diagnostics and transparent pricing, delivering immediate and long-term savings versus many independent shops.
• If the issue is warranty-related, repairs must be completed at a certified Lexus dealership to maintain coverage and ensure proper parts and labor.

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

• Start with obvious items: secure gas cap, visible leaks, and recent fuel type — 2018 Lexus RC 300 requires premium unleaded fuel.
• If basic checks don’t clear the light, an OBD-II diagnostic scan is the next step to retrieve specific trouble codes.
• Nalley Lexus Smyrna’s quick diagnostics locate the fault accurately and can often avoid unnecessary repairs, saving you both time and money.
• Warranty-related diagnostics and repairs should be done at a certified dealership to protect coverage and ensure OEM parts and procedures are used.

How much does a check engine light diagnostic cost for a 2018 Lexus RC 300?

• Diagnostic fees vary, but Nalley Lexus Smyrna offers competitive, transparent pricing and service specials — our certified technicians provide precise scans that help avoid needless work.
• Because we use factory tools and genuine parts, many customers find immediate and long-term savings compared with independent shops that may rely on generic procedures.
• If repairs are covered under warranty, they must be performed at a certified dealership to preserve your coverage; we’ll explain how warranty impacts cost before any work begins.
• We also provide clear estimates for any recommended repairs so you can weigh options with confidence.

How long does a check engine light service take?

• Simple diagnostics and resets can take as little as 30–60 minutes; full diagnostics and repairs depend on the issue discovered.
• Common fixes like sensor replacements or EVAP repairs often complete within a few hours when parts are on hand.
• At Nalley Lexus Smyrna we prioritize efficient scheduling and genuine parts, delivering faster turnarounds and long-term savings through correct repairs done by factory-trained technicians.
• If warranty work is required, performing the service at our certified dealership ensures proper documentation and preserves coverage.