Signs Your Saab’s Oxygen Sensor Is Going Bad

Mechanic One Auto Repair & European Auto Repair are Saab experts, and these cars have been known to come with a few problems. Let’s talk about the oxygen (O2) sensor. This auto part lasts generally 60,000 miles to 90,000 miles after which it goes bad and fails. Once it goes bad, it can no longer report the correct oxygen levels in the exhaust and you’ll notice the following problems.

Failed Emissions Test

When the O2 sensor reports incorrect data, your Saab’s engine control module makes unnecessary adjustments to the fuel mixture. This can create either a rich or lean fuel mixture in the combustion chamber. A rich mixture has too much gas in it and this will cause your Saab to fail an emissions test because there will be too much carbon waste in the vehicle’s exhaust.

Poor Fuel Economy

A rich fuel mixture can also affect your Saab’s fuel economy. The vehicle will burn too much gasoline or diesel fuel, and this will have you running to the service station more often. If the mixture is extremely rich, you might also notice excess black exhaust coming out of your Saab’s tailpipe while you are driving. 

Rotten Egg Smells

A rich fuel mixture inundates the catalytic converter with more fuel than it can handle and this causes it to fail prematurely. The result is your Saab’s engine will overheat and you’ll detect rotten egg smells coming from the engine and the exhaust. It’s important to have the oxygen sensor and catalytic converter problems fixed right away, as the catalytic converter is the part that handles your engine’s carbon monoxide.

Rough Idling/Running

A lean fuel mixture is top-heavy with air. This will starve your Saab’s engine of the fuel it needs to run properly. You will notice that your engine is idling roughly and has performance issues such as sputtering and stalling. If the mixture is seriously fuel-starved, you might not even be able to get your Saab started. 

Service Engine Soon Light

Finally, once the oxygen sensor malfunctions, it will send an error to the engine control module. The Saab’s module will turn on the Service Engine Soon light to alert you that your engine needs to be serviced. The beauty of the engine control module is that we can run a diagnostic test to download the error which will point us directly to the problem, oxygen sensor or not.

Call Mechanic One Auto Repair & European Auto Repair in Canton, MI, to schedule an appointment for your Saab if you suspect the oxygen sensor is going bad or you have other problems. We’ll get your Saab back on the road purring like a kitten.

Photo by Nottpossible from Getty Images via Canva Pro

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