Frequently Asked Questions

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

• Confirm safe driving conditions and look for other warning lights or unusual noises.
• Check the fuel cap: a loose or damaged cap is a common, simple cause and is quick to correct.
• Note symptoms — rough idle, power loss, or exhaust smell — and record when it started.
• Bring the vehicle to Nalley Toyota of Roswell for a fast diagnostic; factory-trained technicians pinpoint the issue and protect warranty coverage.
• Choosing our dealership often costs less than independent shops because of accurate diagnostics, access to genuine parts, and fewer repeat repairs — immediate and long-term savings.

How long does a check engine light service take?

• Initial diagnostic scan typically takes 30–60 minutes; in many cases we can identify the cause the same day.
• Minor fixes like replacing a gas cap or sensor are often completed within an hour.
• More complex repairs (fuel system, catalytic converter, or engine work) can require parts ordering and take longer — we give clear time estimates upfront.
• Scheduling service at our dealership accelerates repairs because we carry genuine Toyota parts and use factory-trained technicians.
• Warranty-covered repairs must be performed at a certified dealership to remain valid, ensuring long-term savings and protection.

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

• It signals the engine control unit detected an emissions, fuel, ignition, or sensor issue that needs attention.
• Common causes include oxygen sensor faults, catalytic converter problems, misfires, or air/fuel mixture issues.
• Ignoring the warning can lead to reduced fuel economy, higher emissions, and more expensive repairs down the road.
• Our diagnostics identify the precise fault code and recommended repair so you avoid unnecessary parts replacement.
• Repairs done at Nalley Toyota of Roswell deliver immediate and long-term savings thanks to accurate diagnostics, genuine parts, and warranty protection.

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

• Diagnostic fees vary by issue but typically fall in an industry range; check our Service Specials for current offers.
• At Nalley Toyota of Roswell we provide transparent estimates after the initial scan so you understand the cost before work begins.
• Choosing our dealership often costs less than independent shops when you factor in correct diagnosis, genuine parts, and fewer repeat repairs.
• Warranty repairs must be performed at a certified dealership to remain valid; this protects your investment and can save substantial money over time.
• We recommend scheduling an appointment online at our service specials page to see current pricing and promotions.

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

• Faulty oxygen (O2) sensors and emissions-related components are frequent causes on this model.
• Loose or missing gas caps, worn spark plugs, or ignition issues are also common and often inexpensive to repair.
• Left unaddressed, these issues can reduce fuel economy and damage catalytic converters, increasing long-term costs.
• Our technicians diagnose the root cause quickly, preventing repeat visits and saving you money over time.
• For warranty-covered concerns, repairs must be completed at a certified dealership to maintain coverage and long-term savings.