Symptoms of Oxygen Sensor Failure in Your Volkswagen
A seemingly insignificant yet rather important component of your engine is its oxygen sensor, or O2 sensor. Your Volkswagen’s O2 sensor reads the amount of oxygen present in your engine’s exhaust fumes. To calculate the most efficient air-to-fuel ratio, it sends the information to your Powertrain Control Module (PCM). When the PCM can’t calculate this ratio correctly, your VW can suffer from several different types of engine problems. That’s why it’s essential to know when your car’s O2 is bad or shoddy. You’ll save yourself lots of time if you can catch the symptoms of oxygen sensor failure early.
Check Engine Light
Like many other engine-related issues, the first symptom you’ll notice is a bright CEL on your dashboard. Since the warning is pretty vague as to the exact problem your engine is having, you’ll need a scan tool to diagnose the issue before making any repairs.
Even though you can buy automotive scan tools online, they require some experience to read and understand correctly, so you’re better off having a trained professional do this step instead. It’s always a safer bet allowing a certified mechanic to diagnose and locate the problems causing your VW’s check engine indicator.
Rough Idling
The air-to-fuel ratio we mentioned earlier plays a significant role in how well your engine runs and idles. Improper calculations can cause your engine to run rich or lean, both of which can result in misfires and throw-off engine cycles. Your VW will run much harder than usual as it either burns too much fuel or too little. Typically, the PCM would regulate these fluctuations based on the amount of oxygen emitted from the engine exhaust. But, as we know, this is impossible if the oxygen sensor cannot produce accurate readings.
Fuel and Emission Problems
For the same reasons that engines run rough when an oxygen sensor is working improperly, engines will burn up too much fuel when oxygen readings in emission are faulty. Two things can happen when your oxygen sensor is shoddy that exasperate greater overall fuel consumption:
- Your engine runs rich and burns much more fuel than necessary to keep itself powered.
- Your engine runs lean and has to burn more fuel to compensate for the drop in power produced by each combustion cycle.
The takeaway here is that a faulty oxygen sensor can be responsible for more frequent visits to the gas station. If you notice yourself pumping gas twice or more a week, you’ll be doing yourself a favor with a visit to a mechanic shop.
You should also be mindful of how higher fuel consumption than usual affects your overall emissions. VWs with shoddy or failing O2 sensors will fail emissions tests 9 out of 10 times because more pollutants make their way past your catalytic convertor. Convertors can only handle so much exhaust fumes at once. Increase that by double the usual amount, for example, and your car will be pushing out a greater amount of CO2 than usual.
Fumes rich in CO2 will smell somewhat like rotten eggs or sulfuric acid, so trust your instinct if you feel like your car is leaving behind a putrid scent.
Munich West: Expert Oxygen Sensor Replacement
European cars require specific service and repair protocols that only trained technicians should be conducting. Even for something 
so simple as replacing an old O2 sensor, it’s always wiser to take your car to a trusted mechanic shop that can guarantee the job gets done right. That’s why Munich West offers dealership-level service at a fraction of the cost, so you can enjoy keeping your car in top condition without having to pay an unreasonable price.
Unlike other shops, Munich West values common courtesy and kindness when it comes to customer service. Your satisfaction is our number one priority. Come in and let our service advisors get to know you and your VW so we can solve all your car problems without any unneeded hassle.
If experience is what you seek, then we’re proud to say that we’ve been serving residents in Decatur, Atlanta, Avondale Estates, Buckhead, Lilburn, Stone Mountain, and Tucker, GA, since 1976. Munich West is the European Repair shop you can trust. To schedule your next visit to Munich West, call us directly at 404-296-6111 today!
