Frequently Asked Questions

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

• Check the gas cap: a loose or damaged cap is a common trigger and an easy fix.
• Verify oil level and visible fluid leaks—low oil can cause related warning lights.
• Look for obvious issues: disconnected hoses, battery terminals, or a hanging wire.
• If the light is flashing, stop driving and have the vehicle towed to our dealership to avoid engine or catalytic converter damage.
• Even for simple fixes, choose our dealership to ensure proper repairs that protect long-term value and warranty coverage—warranty repairs must be performed at a certified dealership.

How much does a check engine light diagnostic cost for a 2018 Lexus IS 350?

• Diagnostics typically start with a computerized scan to read stored trouble codes and live data.
• At Nalley Lexus Smyrna we offer competitive diagnostic pricing and transparent quotes—our service often costs less than independent shops while delivering factory-level care.
• Immediate savings come from accurate diagnosis and avoiding unnecessary part replacements; long-term savings come from preventing major repairs through correct repair procedures.
• If a covered repair is needed, remember warranty repairs must be completed at a certified dealership to retain coverage and ensure OEM parts are used.
• We provide a clear estimate before any work, so you know the investment and expected benefits up front.

What does it mean when the check engine light comes on in a 2018 Lexus IS 350?

• The light indicates the vehicle’s onboard computer detected a fault in emissions, ignition, fuel delivery, or sensors that affect performance.
• Common causes include faulty oxygen sensors, misfires, EVAP leaks, catalytic efficiency issues, or sensor wiring faults.
• Some issues are minor and inexpensive to fix, while others can lead to reduced fuel economy, higher emissions, or engine damage if ignored.
• Our technicians perform a full diagnosis and explain repair priorities so you save immediately and avoid costly downstream failures.
• For warranty-covered issues, repairs must be done at a certified dealership to preserve protections and ensure OEM parts.

What is the most common reason for check engine light on a 2018 Lexus IS 350?

• Worn or failing oxygen sensors and EVAP system leaks are among the most frequent triggers.
• Spark plug or ignition coil issues causing misfires also commonly illuminate the light.
• Minor causes like a loose gas cap are common and inexpensive to resolve.
• Addressing the cause promptly at our dealership often costs less overall than delaying repairs, since we prevent collateral damage and maintain warranty eligibility.
• We provide clear guidance on repairs and expected costs so you can make informed decisions with long-term savings in mind.

How long does a check engine light service take?

• Initial diagnostic scans and test drives typically take 30–90 minutes depending on symptoms and code complexity.
• If repairs are required, simple fixes (gas cap, sensor swap) can be same-day; more involved repairs may require parts ordering and additional time.
• Our dealership’s OEM tools and parts availability accelerate accurate repairs and reduce return visits compared with slower, trial-and-error approaches.
• Choosing Nalley Lexus Smyrna often yields immediate and long-term savings—fewer repeat repairs and preserved resale value—while warranty repairs must be done at a certified dealer.
• We provide estimated timelines and keep you informed throughout the process to minimize inconvenience.