N. Washington St

(701) 795-5164 ext 1

S. Washington St

(701) 780-8833 ext. 2

Check Engine Light Diagnostics

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Why Is That Light On?

There are numerous reasons why your check engine light is on. The most simple cause is a loose gas cap. The onboard computer will read this as a problem. If tightening your gas cap doesn’t make the light go off, you might be dealing with a more severe issue.

Catalytic Converter

One check engine light issue you don’t want to ignore is the catalytic converter. Not only will it affect your car’s performance, but you will also fail your next emissions test. The catalytic converter functions as a filter to keep pollutants and gases from your engine. The best fix a complete replacement of the converter.

Flashing Engine Light

If you see this, bring your car to our shop immediately. A flashing check engine light indicates unburned fuel is being dumped from your engine into its exhaust system. It causes dangerous engine misfires. It could lead to your engine catching on fire. A tow truck is advisable in this situation.


Your engine’s multiple sensors could be experiencing a leak. A leak in the O2 sensor is a common culprit. The O2 sensor monitors the amount of unburned oxygen in your engine’s exhaust. When the O2 sensor is worn or defective, the check engine light comes on. The only fix is a replacement. If you leave it in a state of disrepair, you will experience poor performance and fuel mileage. Another troublesome leak is one in the EVAP system or a vacuum leak. The EVAP keeps gas fumes out of your engine and car. Another function is keeping the number of pollutants your vehicle emits low. Your EVAP system leaks if it has a loose seal or o-ring. If you don’t get this repaired, you will start smelling gas in your car. If you experience frequent stalling, there could be a vacuum leak. A loose hose going to your engine causes the leak. You will need this hose tightened or replaced.