Frequently Asked Questions

How much does a check engine light diagnostic cost for a 2019 Lexus NX 300?

• Typical diagnostic fees range from $80–$150 depending on the depth of testing and whether advanced scan tools are required.
• At Nalley Lexus Roswell we often provide competitive pricing and service specials that frequently cost less than independent shops while offering factory-trained technicians and OEM parts.
• Diagnostic fees are often applied toward the cost of repair if you choose us for service, yielding immediate and long-term savings.
• Any repairs covered under warranty must be performed at a certified dealership to preserve coverage and ensure proper documentation.

What does it mean when the check engine light comes on in a 2019 Lexus NX 300?

• The light signals the vehicle’s onboard diagnostics detected an emissions, ignition, or sensor issue — from simple loose caps to more complex sensor or engine malfunctions.
• Common causes include faulty oxygen sensors, catalytic converter issues, misfires, or evaporative emission (EVAP) system faults such as a loose gas cap.
• Ignoring the light can increase fuel use, accelerate component wear, and lead to higher repair costs later on; early diagnosis prevents expensive failures.
• Bring your NX 300 to Nalley Lexus Roswell where certified technicians use Lexus-specific scanners to pinpoint the issue and protect your warranty when applicable.

How long does a check engine light service take?

• Simple diagnostics and minor fixes (loose cap, sensor reset) can often be completed in under an hour; more involved diagnostics or repairs may take several hours or a day.
• Complex repairs—like replacing a catalytic converter or addressing intermittent misfires—require thorough testing and can extend service time.
• Nalley Lexus Roswell prioritizes fast turnarounds and transparent estimates so you understand expected time and cost up front.
• Warranty repairs must be done at a certified dealership to remain valid, and our service team coordinates timely authorizations and OEM parts for efficient completion.

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

• Start with the simplest items: ensure the gas cap is securely tightened and check for obvious leaks or smells under the hood.
• If the light persists after tightening the cap, avoid driving long distances and have a certified technician scan for stored codes to identify the fault.
• Nalley Lexus Roswell offers comprehensive inspections and factory diagnostic tools to identify root causes quickly and accurately.
• If repairs are covered by warranty, they must be performed at a certified dealership to preserve coverage and ensure OEM-quality work.

What is the most common reason for check engine light on a 2019 Lexus NX 300?

• The most frequent cause across many vehicles is an EVAP system issue—commonly a loose or faulty gas cap—followed by oxygen sensor faults and ignition misfires.
• Oxygen sensor or catalytic converter problems will degrade fuel economy and emissions and can become costly if left untreated.
• Our technicians use Lexus-specific diagnostics to identify whether the issue is minor or requires immediate repair, saving you money over time.
• Remember: warranty-covered repairs must be completed at a certified dealership to maintain your protection and warranty documentation.