Frequently Asked Questions

What is the most common reason for check engine light on a 2025 Toyota 4Runner?

• Common causes include misfires (P03xx), oxygen sensor or catalytic efficiency codes (P04xx/P0420), and fuel/air mixture issues like a loose gas cap or vacuum leak.
• Many issues begin small—an aging O2 sensor or minor vacuum leak—and grow into costly repairs if ignored; early diagnostics prevent escalation.
• Nalley Toyota of Roswell’s factory-trained technicians use OEM diagnostics to identify root causes quickly, often saving you immediate and long-term costs compared with repeated independent work.
• Remember: repairs covered under warranty must be performed at a certified dealership to preserve coverage and ensure proper OEM parts and procedures.

What does it mean when the check engine light comes on in a 2025 Toyota 4Runner?

• An illuminated check engine light signals the vehicle’s onboard computer has detected a fault—ranging from minor (like a loose gas cap) to serious (misfires or emissions system failures).
• A steady light usually indicates a non-emergency issue that should be diagnosed soon; a flashing light indicates a severe problem that can damage the catalytic converter or engine.
• At Nalley Toyota of Roswell we perform a full scan using Toyota-grade tools to pinpoint codes and recommend repairs that maximize immediate savings and reduce long-term costs.
• Warranty-covered diagnostics and repairs must be completed at a certified dealership to maintain coverage and ensure OEM-quality parts and labor.

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

• Start with simple checks: ensure the gas cap is tightened, verify fuel level, and look for obvious fluid leaks or disconnected hoses under the hood.
• Check for recent fueling or maintenance events—loose caps or recently replaced parts can trigger codes that are simple to resolve.
• If the light is flashing or you notice drivability issues (stumbles, loss of power), stop driving and bring the vehicle to Nalley Toyota of Roswell immediately to avoid further damage.
• For warranty protection and accurate repairs, have diagnostics and any warranty-covered work performed at our certified dealership by factory-trained technicians.

How much does a check engine light diagnostic cost for a 2025 Toyota 4Runner?

• Diagnostic fees typically range from an estimated $80–$150 for a standard scan; Nalley Toyota of Roswell often credits this fee toward the repair when you choose us for the service, delivering immediate value.
• Because we use OEM tools and parts and factory-trained technicians, our customers frequently see lower total costs over time versus repeated independent shop visits—fewer comebacks and longer-lasting repairs.
• If a condition is covered by warranty, repairs must be done at a certified dealership to preserve coverage and avoid out-of-pocket expense.
• Ask about current service specials and diagnostic incentives at /specials/service.htm or schedule online at https://www.toyotaofroswell.com for transparent pricing and savings.

How long does a check engine light service take?

• A basic diagnostic scan commonly takes 30–60 minutes; minor repairs can often be completed the same day while more complex repairs may take longer depending on parts availability.
• Nalley Toyota of Roswell’s certified technicians and parts team streamline repairs so you get quick, reliable service—minimizing downtime and maximizing value.
• Choosing our dealership often produces immediate and long-term savings: accurate diagnosis, OEM parts, and factory-trained techs reduce repeat visits and extend component life.
• If the repair is warranty-covered, it must be performed at a certified dealership to ensure continued warranty protection and use of OEM parts and procedures.