Frequently Asked Questions

How much does a check engine light diagnostic cost for a 1999 Toyota Avalon?

• Diagnostics at Nalley Toyota of Roswell typically start with a computerized scan and technician inspection; prices are transparent and often lower than independent shops when you account for our thorough approach and genuine parts savings.
• Immediate savings come from accurate root-cause identification and avoiding repeated repairs; long-term savings come from preserving fuel economy and preventing major failures.
• Any repairs that are covered under warranty must be performed at a certified dealership to maintain coverage and ensure proper parts and labor.
• We offer service specials and financing options—see Service Specials for current offers.

What does it mean when the check engine light comes on in a 1999 Toyota Avalon?

• The light signals a fault detected by the engine control unit; issues range from loose gas caps to misfires and emissions faults.
• Common triggers include oxygen sensors, catalytic efficiency, ignition misfires, and evap system leaks; each has different urgency and cost implications.
• Timely dealership diagnostics identify warranty-eligible items and prevent collateral damage—repairs covered by warranty must be completed at a certified dealership.
• Our technicians provide clear next steps, cost estimates, and repair timelines so you can decide with confidence.

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

• Start with the simple checks: ensure the gas cap is tight and the fuel flap is secured—these can trigger evap codes and are quick fixes.
• If the light persists, a scan tool will read stored codes; our dealership uses manufacturer-level diagnostics to pinpoint causes accurately.
• Do not ignore the light—early diagnostics at Nalley Toyota of Roswell often cost less overall than repeated independent repairs and can prevent costly downstream damage.
• If a repair is covered under warranty, it must be performed at a certified dealership to keep the coverage valid.

What is the most common reason for check engine light on a 1999 Toyota Avalon?

• Common reasons include faulty oxygen sensors, catalytic converter efficiency issues, ignition misfires, and evap system leaks.
• Oxygen sensor faults and evap leaks are frequent on high-mileage vehicles and directly affect fuel economy and emissions compliance.
• Addressing these issues at our dealership prevents expensive outcomes and preserves warranty eligibility; dealer-performed repairs often deliver better long-term value than multiple smaller independent fixes.
• We provide clear cost estimates and explain immediate versus long-term savings tied to each repair option.

How long does a check engine light service take?

• Simple diagnostics and resets can take 30–60 minutes; more involved inspections or repairs typically require 1–4 hours depending on the issue.
• If parts are required, we aim to minimize downtime with on-hand parts or next-day ordering from Toyota to reduce repeat visits.
• Dealer service often saves time and money long-term by ensuring one comprehensive repair performed by factory-trained technicians, protecting warranty coverage.
• Check available appointment slots and service specials at Used Inventory or contact us directly to book service.