My girlfriend's new car had its "Service Engine Soon" warning light come on. She took it to her friend's husband, who hooked it up to something to show why this light was on. He said the computer stated it was her oxygen sensors but that it was no big deal. Several hours later the light eventually went off. My question is what are oxygen sensors on automobiles and what is their purpose? If they are no big deal then why did they trigger that light to come on? Any information will be greatly appreciated. Thanks in advance.
You can get a replacement one for like 60 bucks at autozone or 230 bucks at the dealership. If you have a bad oxygen sensor your gas mileage might suffer.
They're there for emissions. Having the light go on is not indicative of a engine problem - thus no big deal. It is a big deal if that light is on during your inspection. No pass.
When I worked at Enterprise, we used to get 'check engine' lights on all the time. We would unplug the battery for about 30 minutes, then plug it back in. The light would never come back on.
Yeah I know "Service Engine Soon" lights come on for simple reasons some times, such as your gas cap isn't tight enough, but sometimes there can be a major problem. Was not sure what oxygen sensors were for but it appears they are no big deal.....well if they deal with gas mileage and with the prices these days they may very well be a big deal but nothing too extreme. Thanks for the quick responses.
Is it a Honda? My engine light came on so I read the manual. Sometimes it can be triggered by a loose gas cap. The light went off then came on again. I decided to take it in and they said the oxygen sensors had to be replaced. I bent over and let them eff me in the arse. I don't know about you but I don't want to drive with the engine light on...scares the crap out of me.
The sensor on most newer cars are digital ones so they have some built in test they do. If the built in test fails then something might be wrong. The oxygen sensor basically tells the car how much fuel to inject so the engine operates efficiently.
Oxygen sensors will effects the cars gas mileage and efficiency. they basically will send information to the computers in your car to adjust the fuel mixtures and things like that. Depending on the car you might have some pre-cat and then some after the cat. It's a good idea to eventually change them because your car will end up driving sluggish after a while. O2 sensors and your Air flow meters really effect performance. On your Nissan it can be a do it yourself job. You might find some tutorials online on how to change it. Just depends if you are willing to do it.
The cost will depend on whether your car is newer and complies with California emissions or an older car that does not. If it complies with California emissions the cost to replace the oxygen sensor will be more expensive. I had to get mine replaced a while ago and it cost $130 for part and install. If I had California emissions it would have cost at least $200 for part and install.
A check engine light showing an o2 sensor issue may not actually be because of a bad o2 sensor. The code may show that the o2 sensor is reading a "rich" or "lean" condition and alot of techs just see "o2 sensor" and want to replace it. If the check engine light came on and then went back off, I would suspect an underlying problem with the emissions, which greatly vary depending on how the vehicle is being driven at that time, more than I would the o2 sensor itself. Normally, the o2 sensor will fail not fail intermittently, but "catastrophically" which would leave the check engine light on permanently until it is replaced and the codes reset. However, it could very well be the sensor itself. I've seen stranger things.
Does this really work? I don't care about my check engine light because it's been on for a long time. I need to have my car inspected though and they won't do it with the light on. Actually for the last three days it has been off so I decided to take it in today to get inspected. Sure enough, the light came back on. I'd like to get the light to turn off for long enough to get it inspected.
I agree. Not saying it couldn't happen, but I've never seen an O2 go bad and then become ok. Throwing the code out, if it were my car and it were an intermittent problem, I'd replace the gas cap for $6.
I don't disagree. but other issues could be present. o2 sensor is the cheapest fixed which is why it is often misdiagnosed.
You might need more info before you go changing the sensor. For instance which sensor it it. My car has 4.
i had my check engine light on for over 2 years because it needed a new oxygen sensor. it was a civic and I never noticed a gas mileage problem. If anything, I would have sworn it was improved.
I took my car to autozone because of the check engine light. After the test he said i needed to replace my trans celenoid shift. That was like 6 months ago. should i change it now...whats going to happen?
