Q: O2 sensor failed

asked by on February 05, 2016

I let my truck sit over the weekend and it won't start. The oil level is fine, but the light did come on, telling me to change it, before I parked it. I am also losing coolant.

Check Engine Light is on Inspection $79.99 - $99.99 Get a Quote
Catalytic Converter Replacement $291.63 - $3214.07 Get a Quote

Hi there. A p0420 usually means the catalytic convert is not performing as well as it needs to. Over time, the catalytic converters fill up with carbon and and will not filter out the exhaust gas as efficiently as they should, which means a replacement is needed. I would recommend having a technician, like one from YourMechanic, inspect for any error codes and replace the catalytic converter if necessary.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Oil change - Synthetic 5k or 10k?

You should follow the dealer or manufacturer recommended change intervals. Your vehicle calls for oil changes every 6 months or 5,000 miles. Using a different oil that is synthetic you still should go with recommended intervals since the oil filter...

2001 Ford Taraus, warning light that looks like gear for a chain on bicycle.

Hey there. The symbol you are describing is for a problem in the transmission. The transmission can have several issues such as slipping problems, hard shifting, stuck gears, or internal damage. If you need a diagnosis of the warning light,...

how many valve lifters do i have in my vehicle?

Most vehicles use regular fuel. If your vehicle says premium fuel only on fuel gauge then you will need to add premium fuel to run the engine properly. As far as lifters you have cam followers if it is an...

What is the correct driving posture for my car?

Driving safely requires that you have the right position and posture when you’re behind the wheel. Not sitting properly in the seat can limit your view, limit your control of the vehicle, and put you, your passengers and others on...

my corrola, while driving suddenly slows down, specially while driving at a 120 kms speed suddenly the speeds slow down and the pu

If you are driving at 120 mph, it is possible that your vehicle is hitting the speed governer. This speed governer will prevent the vehicle from going past a certain speed by limiting engine power and reducing rpms. Not all...

Where is the transmission mount of the 1998 Toyota Camry located?

The mount is beneath the transaxle on the driver side. The Toyota OEM mount is recommended if you desire to replace this part. If you need help with this, please request engine/transaxle mount replacement and the responding certified mechanic will...

Engine misfire

Hi Dave, Engine misfires can be caused by many different problems and are generally caused by either a spark or fuel issue or in some cases, a combination of both. Spark related problems generally will result from things like ignition...

Car turns on and off. The brake and the steering wheel gets harder.

Hello, thanks for writing in. The P0171 is an indication of a lean mixture, which can be caused by an air leak in the intake (as you were advised), a borderline engine temp sensor reporting a warmer engine temperature than...

Brakes hiss when I use them

Well, it sounds like you may have a vacuum leak coming from the brake booster. I definitely recommend you do not drive the vehicle until you have an independent mechanic look over it, as this is a major safety concern....

Related articles

2012 Toyota Camry vs. 2012 Chevrolet Malibu: Which One Should I Buy?
Mid-size sedans are the perfect family vehicle; offering just enough space for you and a few kids, but not so much that a small family will feel lost in them. This class of vehicles is slightly larger than a compact...
How Your ECU Uses Sensor Data
Today’s Today’s modern vehicles are made up of anywhere from one to seven computers that assist with the car’s day to day functions. An engine control unit (ECU), is a computer that similar to that of a laptop or smartphone...
Where Is the O2 Sensor Located?
Oxygen Oxygen sensors O2 sensors will always be located in the exhaust system. Their function is to sense how much oxygen remains in the exhaust that is flowing out of the engine, and report that information to the vehicle’s engine...