Frequently Asked Questions

How much does a check engine light diagnostic cost for a 1991 Toyota Corolla?

• Typical diagnostic fees vary by complexity but are often a modest flat rate for code reading and initial inspection.
• At Nalley Toyota of Roswell we frequently cost less than independent shops while providing factory-trained technicians and OEM testing equipment.
• Choosing our dealership yields immediate savings through accurate diagnostics and long-term savings by avoiding unnecessary repairs and protecting warranty coverage.
• Any warranty-covered repairs must be performed at a certified dealership to maintain coverage and ensure proper parts and documentation.

What does it mean when the check engine light comes on in a 1991 Toyota Corolla?

• It signals the vehicle’s onboard diagnostics detected a fault — from emissions systems to engine misfires or sensor failures.
• Codes can indicate minor issues (like an evap leak) or serious problems (misfires that damage the catalytic converter).
• Accurate code reading and interpretation by factory-trained techs determines severity and next steps.
• Prompt dealership diagnosis protects performance, fuel economy, emissions compliance, and warranty coverage.

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, easy-to-fix cause of an emissions-related code.
• Look for obvious signs—smoke, fluid leaks, or unusual noises—and avoid extended driving if severe symptoms appear.
• Bring the vehicle in for an OBD-II scan so our technicians can read stored codes and recommend the correct repair path.
• If repairs are covered by warranty, remember they must be performed at a certified dealership to keep coverage valid.

How long does a check engine light service take?

• Simple code reads and minor fixes—like tightening a gas cap or replacing a sensor—can take under an hour.
• Repairs requiring parts, further diagnosis, or engine work typically take a few hours to a day depending on parts availability.
• Our dealership emphasizes efficient scheduling and thorough inspections so you get accurate fixes that prevent repeat visits.
• Using Nalley Toyota of Roswell often saves time and money long-term because factory-trained techs fix the root cause correctly the first time.

What is the most common reason for check engine light on a 1991 Toyota Corolla?

• Common causes include a loose gas cap, failing oxygen sensors, ignition misfires (spark plugs/wires), and evap system leaks.
• Older vehicles also often show codes for worn sensors or catalytic efficiency loss; early diagnosis prevents escalation.
• Our factory-trained technicians quickly identify the root cause and recommend OEM parts to restore reliability and efficiency.
• Choosing the dealership supports warranty integrity and can cost less overall than independent shops when considering long-term reliability.