So I got a car last week from a car lot and just got an oil change today. During the oil change, the worker said there were a few things wrong with it, including a bad exhaust sensor. After googling, it shows an O2 sensor. Since I got it, when the car has been sitting there for a while, I turn it on and it automatically shuts off, I turn it on again and press the gas and it goes. Can this be because of the O2 sensor? The mechanic at the car lot said it could be because of the loose fuel cap but after replacing it and this shop resetting the engine light, it still comes on. Not only that, it’s gotten worse. It turns off 2 or 3 times before staying on and hesitates like it wants to shut off when pulling out. Once I’m on the road driving, it stays on. Today I stopped at a stop light and it shut off. I need to get this fixed asap but dont want to waste money on the wrong thing. Please help.
You need to take the car to a qualified mechanic for a proper diagnosis and repair. That is not going to be a technician at an oil change facility.
Was the Check Engine light on when you test-drove the car? I find it hard to believe a registered car dealer could legally sell you a vehicle in that condition.
Yes it was on and I questioned it, he had thier mechanic scan it and it came back and said it was reading an o2 sensor and that it was because the fuel cap was loose and reset the code. He suggested buying another one which I did, but it’s still there.
If you signed papers that said sale of vehicle was ’ As Is ’ then you are stuck unless you had a return period . If you can return this thing that might be your best move. Otherwise you are just going to find a shop and pay for the repairs.
An oxygen sensor code will not be fixed by replacing the gas cap. You have been taken advantage of by an unscrupulous dealer. You may need to take legal action because they will undoubtedly deny the Check Engine light was on in the first place. I take it you got no warranty on the car, but you may have some recourse, depending on what state you live in.
I had an 08 Vue for 100,000 miles, with many mysterious problems. Not sure which engine you have, but mine was the I-4. The O2 sensor didn’t affect the performance—just had to be replaced to get the dash light to turn off. Did it myself—was easy, but there was a lot of room with the small engine.
The problem I had was the car would run, but wouldn’t idle. Turned out that cleaning the throttle body helped the most—another cheap, first-thing-to-try. Disconnect battery cables for all work, and reserve judgement until at least 100 miles; my mechanic explained whenever the battery is disconnected, the car takes a while to relearn its tune.
The O2 sensor isn’t used by the engine computer until the engine warms up enough for the sensor to start working. Engine performance problems immediately after cold starts aren’t caused by faulty O2 sensors. To get further help here, post the diagnostic codes from the computer memory. They’ll have numbers starting with a “p”, like p0301, etc. A little advice: When purchasing a used car Tom and Ray’s advice has always been to have the car inspected by your own mechanic before writing any checks. Also don’t even both to take it to your own mechanic for inspection if the check engine light doesn’t come on w/the key in “on” and the engine not started, and then doesn’t go off immediately after starting the engine. That said, there’s a pretty good chance whatever’s wrong in this situation won’t be super-expensive to repair. But don’t try to repair it by replacing parts on a guess. Very easy to run out of money before running out of guesses.
The O2 sensor is probably working correctly and has detected a problem, before replacing the O2 sensor, get the codes read and post back.
There are many things that can trigger an O2 sensor code, and just replacing the O2 sensor doesn’t fix the problem.
Thanks for all the advice, I’m going to go have it scanned later on today and post it back here once I have them.
After thinking about it, it sounds a lot like it could be the throttle regulator - about $40 - 60 at pretty much auto parts store.