What the psychology behind that? I replaced the oxygen sensor in my wife’s car that was throwing a “check engine” light. I drove it to test it after I replaced the sensor and it drives pretty much as well as it always did. My wife disagrees. She says it run phenomenally better which it really doesn’t (and she only drove it 2 miles 
).
So what is the psychology behind people getting an oil change or indeed only “washing” their car thinking that it then runs so much better?
I’m the opposite. If I don’t have at least one warning light on, I start to worry.
Some years ago, when I had my first car, I used to wash the windows occasionally. Especially whenever it ran rough or otherwise didn’t seem to be running as best it could be. I always figured if I washed the windows, that would appease it and it would be happy and run better for me.
Yes it does.
The world is also a better place when the vehicles windows are clean.
A clean engine is a happy engine, and as such, I’ve never allowed them to get dirty in the first place: slightest coating of dust, mist with cleaning solution, carefully rinse off, drive to dry it off.
It runs better. Seriously.
I find my car is more aerodynamically efficient when washed and waxed. Handles better too.
I wouldn’t be so sure. People know their own car. I know when something small is off that my wife misses and I have to point it out to her. In this case driving style could be why also. The O2 sensor will change the air fuel ratio, that effect could be more or less pronounced at different throttle/rpm/load levels.
I have the same thing, need an oxygen sensor. But I put off getting it fixed for several months now. Could it damage the catalytic convertor or engine or am I just not getting good gas mileage. That’s not an issue for as I drive less than 200 miles a month
Shenanigans! I power-washed my engine and it never ran again!
Try explaining to someone that, no, their car does not stop better when they get new brakes put on. Assuming they weren’t down to metal on metal, you’re typically replacing before you lose any braking ability.
Depends. Depends which sensor, depends what it’s doing. I’d be willing to guess that if the front O2 sensor is reporting lean and the ECU starts dumping fuel into the engine, that could cause a problem. I assume (and it’s nothing more than an assumption) if it got to that point, you’d be noticing more problems than just the CEL on.
I would assume that cars are now smart enough that if they know there’s a problem with an O2 sensor, they don’t adjust the short term fuel trims or stay in open loop mode. IOW, they find ways to ignore the data they know is wrong (or missing).
But again, I have no idea, it’s just an assumption on my part.
What JoeyP said. I would only add that while it is definitely not an issue where you need to park your car and have it towed somewhere, or even put off the weekend trip because of it, it is something that needs fixed sooner rather than later. I can’t help but think that long term it will do some damage to your car because the computer system is not able to provide the proper fuel/air mix to your engine.
I got lucky because it this car (09 Sentra) it is literally right there behind the manifold with relatively easy access. Just need a ratchet with an extension and a special 22mm oxygen sensor socket–specially made with a little cut out on one side so you don’t crush the wire coming off of it—and there you go. Really easy, however to replace spark plugs you have to remove the entire intake manifold which pisses me off. That is above my pay grade so it will be a brother in law job. 
If it’s a rear O2 sensor, I think you’d be okay forever. To the best of my knowledge, the rear O2 sensor is essentially just monitoring the health of the cat, but the computer doesn’t use it’s input to make adjustments to anything.
And as I say this, my wife came home a little bit ago and the (bad words) check engine light came back on!
I’m a procrastinator and forgetful, and times goes by faster than I realize sometimes. I know it’s the sensor because I had it scanned at AutoZone. About a year earlier, I had to replace the catalytic convertor, the check engine light was on when I got inspected. A few months later it came on again and I thought maybe it had been installed badly. It was not that but the sensor. But now I remember it was in December when I had the scan done. Car runs just fine and it also has over 110k miles. So I don’t want to spend a lot on repairs, but if it would only be a couple hundred I would do that. But it may be the computer, my brake light is always on and so is the tire pressure light, even though I know the tires are at the proper level.
I’m due for an inspection in a few months, I’ll just wait until then. I know it will not pass with that light on
I know it’s just in my head, but when I clean my car inside and out it feels like it runs smoother. It’s a fairly new car - 2017 with not yet 20,000 miles on it so there are no issues with it at all. But it sure feels smoother when it’s clean!
I took it back and had it scanned and it is still throwing the same O2 code again. If I clear it and run it for a while it stays off. Then it will come back on again, sometimes after a few minutes and sometimes after more than a day of constant driving. JoeyP any ideas?
I did check the resistance on the sensor and that is not the issue. It’s a good sensor. One thing I did notice is that the air filter housing is cracked and does not hold the air filter in firm. There is a gap of about 3/4 of an inch. I saw that before and pushed it back tight. What are your thoughts about a good zip tying holding it in place solving the issue or am I down a rabbit hole?
Going to throw this out for your O2 sensor/catalytic converter problem.
Wife’s Dodge minivan check engine light came on. Faithfully went to the dealership and was informed the code was for a bad catalytic converter, estimate to replace $800+. Found out with these years of Dodge/Chrysler products you can turn the key on/off/on and the code will show up in the odometer spot. Googled the code and yes, catalytic converter fault. Also googled how to repair this fault and it was suggested that the readings between the 2 sensors may be off due to the sensors getting “coated” from using cheap gas, which my wife usually got, and gave a false code.
3 bottles of Chevron Techron over several tanks of gas and the code went away. Year later the code came back. Redid the Techron thing and it went away and never came back. Sold the van so don’t know how long that treatment lasted. Trust in the dealership was shot as they also told us our non-woking slider door needed to be replaced for $1200 when a google search showed 95% of the time it was a broken wire that was too short from the factory. Yep, a hour of my time fixed a problem the dealership wanted $1200 for.
Google the code and see if there may be other issues setting the code off. Also have heard that unhooking the battery for an hour, or overnight, will reset some of the codes and clear the “memory” of the previous faults.
I always try to get “Top Tier” gas and surprisingly, unlike my wife and her cheap gas, I never had fuel related or emission codes on any of my vehicles.
Disconnected the battery for a few hours and the check engine light is now off, but the brake light is still on. When you get your car scanned at a dealer, or AutoZone, does it simply read the car’s computer or does it check independently? If the former, how would you ever know if the computer is in error? Can you tell if an oxygent sensor is bad just by looking, assuming there is no obvious physical damage?
ETA I’m going to start using premium gas, especially since I don’t put many miles on the car.