Frequently Asked Questions

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

• Check the gas cap for a loose or damaged seal — a common cause on a 1990 Toyota Land Cruiser that can trigger an emissions fault code.
• Look for obvious signs: low oil, unusual noises, smoke, or a sudden loss of power that require immediate attention.
• Note any recent fueling or maintenance events and try tightening the gas cap; if the light persists, schedule a diagnostic.
• For safety and warranty protection, have any necessary repairs performed at Nalley Toyota of Roswell’s certified service center.

What does it mean when the check engine light comes on in a 1990 Toyota Land Cruiser?

• It indicates the vehicle’s onboard diagnostics (OBD) detected a system fault — anything from an emissions sensor issue to an engine misfire.
• Common causes include oxygen sensor failures, catalytic converter problems, ignition misfires, mass airflow sensor faults, or EVAP system leaks.
• Some faults are minor, others can damage components if left unaddressed — timely diagnostics protect engine and emissions systems.
• Bring your Land Cruiser to Nalley Toyota of Roswell for accurate scanning and recommended repairs covered by certified-warranty procedures when applicable.

What is the most common reason for check engine light on a 1990 Toyota Land Cruiser?

• The most frequent cause is a faulty oxygen (O2) sensor or a loose gas cap — both affect emissions and fuel trim readings.
• Other common issues include ignition misfires, worn spark plugs, or EVAP system leaks that trigger stored trouble codes.
• Early diagnosis at our dealer minimizes repair scope and expense while preserving long-term reliability of the 4.0L inline-6 engine.
• Nalley Toyota of Roswell uses factory diagnostic tools and trained technicians to identify the real cause and ensure warranty compliance.

How much does a check engine light diagnostic cost for a 1990 Toyota Land Cruiser?

• Diagnostics at Nalley Toyota of Roswell are competitively priced and often cost less than independent shops when you factor in accurate results and long-term savings.
• Typical scan fees can be low, and if repairs are needed, our transparent estimates show immediate savings through correct parts and long-term savings by preventing further damage.
• Many warranty-covered repairs must be performed at a certified dealership to remain valid — we handle those repairs to protect your coverage.
• Check our current Service Specials for offers: Service Specials, and schedule a diagnostic with factory-trained technicians.

How long does a check engine light service take?

• Simple diagnostics often take 30–60 minutes; more involved troubleshooting for intermittent faults or misfires can require several hours or a scheduled appointment.
• If parts are needed, repair time depends on part availability; Nalley Toyota of Roswell keeps many common parts on hand to reduce downtime.
• Our factory-trained technicians prioritize accurate diagnosis to prevent repeat visits — that saves time and money over independent approaches that may clear codes without fixing root causes.
• We recommend scheduling online through our Service Specials page or contacting the service center for an estimated completion window.