I'll try to explain more.
What the article you linked to is trying to say is that you shouldn't just a replace the O2
sensors if the CEL
comes on without knowing anything more about why the CEL
came on. However, if you read the code and it's an O2
sensor performance code like P0133 or P0130 then you almost always end up having to replace the sensor to make the code go away. However if the code is much more generic like P0171/P0174 then you need to do more investigating before you replace the sensor. Many poorly-educated folks automatically associate lean codes with bad O2
sensors, which is almost never the correct cause. So this is why it's important to know the exact trouble code and do the correct troubleshooting before you replace an O2
As far as driving with the CEL
light on, the issue there is that you don't know if you have a serious problem or not unless you know why the CEL
is on. Yes, some of the codes are very minor and you could drive around for years without a problem, but some of the codes are more critical and cause expensive damage if they are ignored for more than a few hours worth of engine operation. The other big issue is if the CEL
is already on and your car develops another more serious problem, you will have no way of knowing it unless you own a scan tool and check your car for new or different codes on a regular basis. Most people that drive around with the CEL
on are clueless to this, and suddenly their car starts having all kinds of problems and requires all kinds of expensive repairs. That pesky single code they had checked six months ago has suddenly morphed into six codes and they had no idea until the damage had already been done.
Now specifically in terms of O2
sensors not working, the fact is that modern cars are almost completely reliant upon the O2
sensors functioning. Yes the car will still run with a missing or poorly functioning O2
sensor, but you end up paying the price in lost performance, poor fuel economy, or with having to replace the catalytic convertors (which costs several hundred dollars or more). A new O2
sensor is only about $40, so it pays to replace it in many ways. Some people even change them as preventative maintenance at about 80-100k.
So the key to all this advice is proper information about the status of the car. In order to make an informed decision and save the most money, you need the most information. I've seen many cases where people ignore the CEL
because they were afraid of the expense, but then ended up wrecking the engine and were left without transportation. I don't like to see that happen, especially when it is very preventable. You can get codes read for free, and I always provide free advice, so it just requires a little effort and info gathering on the part of the car owner to get some decent help. Once you know the situation and the risks, then you can decide how to spend your money wisely.
Again, in your situation drive the car normally for now. If the light comes back on, go get the code read and report back to us before you buy anything. If you still have to get to work, then you have to drive the car, but my main point is to not completely ignore the light for weeks or months on end without intending to have it checked out. This sounds like a car in very good condition otherwise, so I would hope it stays that way.