I searched the forum, AND talked to some mechanics and haven't gotten any real answers. I believe these are all different issues but they may not be.
I bought a used 2001 corolla last year with about 180k on it and it had a check engine light on. On my initial read from a used car inspection, the mechanics told me that everything was fine and the check engine light was just saying the CAT needed to be replaced.
I bought the car, went to a place that changes cats and the guy told me he didn't want to change it because he has no idea if it's actually the cat so i shouldn't waste my money and to take it to a mechanic and see if that is even the problem at all.
I had since taken it to three mechanics and they ALL are telling me different stories. One says it's probably the O2 sensors bad or dirty, another says it could be anything so just start changing the cheaper parts first till the problem is fixed, and another says the check engine light will possibly never go out even if you change everything that is realted to that code. .... ?!!! is there a tool or meter of some sort to check the O2 sensors? aren't they electronic?......
well, that was the first problem.
second, the car does that studdering thing people are describing but i believe it's a little different on mine. This happens very rarely but it really bothers me when I'm in the middle of an intersection trying to turn left. basically, from a stop at a red light or while waiting to turn or get into a moving lane, SOMETIMES the car will not move. I step on the accelerator, and there is nothing. The car doesn't move, the RPM gauge doesn't move, the engine doesn't make any noise... literally nothing. I can sometimes avoid this by turning off the overdrive but it doesn't always work. Like someone else mentioned, it's usually when i'm going from stop to half throttle, but it's done it sometimes even when i'm pressing really light on the gas. it does this maybe once a week and i drive really carefully now. make sure i have enough space between me and the travelling car should mine not move. when it finally does move there is a little studdering before it get's back up to speed. it does this on hills as well so i try to make sure the overdrive is off when i approach hills. this happens mostly when the car is warm, i actually don't ever remember it happening when it was cold. and it never does this in park.
third, my oil went almost completely dry, and it had been about three months overdue for an oil change, but the last time i went six months, it was only low by a quart. this time it was low by about 2 quarts. I only knew this because i had to accelerate out really quick onto a busy street and it made this really loud metallic whirring sound, almost like a car with a timing chain instead of belt (which i noticed this car kind of sounds like anyway... or maybe my pulley bearings are bad...??) and the oil light went on so I immediately knew what it was and turned into a gas station and put in some oil. I use 5-30 syntec but they only had synthetic mobil1 so i filled with that. I remember one of the first cars I had I was using royal purple and i didn't know there was a gasket leak, was running the car dry for months, so i'll check my oil every month now to see if there is a problem beyond normal consumption. but i'm wondering if i should switch to higher mileage oil now and see if there is a difference in rate of use.
fourth, the most recent problem is there is a not loud but noticeable whining, vibrating, noise, almost like an industrial vent fan that needs to be lubricated (i work at a restaurant). It's coming from the engine compartment but I can't tell where cause this engine is so damn noisy compared to my old 95 corolla. I know the power steering noise and it's not that because one, it sounds different, and two, the noise goes away when I apply pressure to the wheel in either direction. goes away when i turn it, comes back when i let go of the wheel. power steering and belt issues work opposite of that right? noise when you turn the wheel?... I am assuming this is an easily identifiable problem but the shop I called can't give me any info and they want me to just bring it in for them to "take a look at"... really? it's opposite of the usual power steering leak noise. You have NO IDEA what it could be? I can't search for this cause all I get is power steering issues in my search results. I also just noticed that the whining pitch gets lower when I accelerate but I cant tell how much lower cause there's engine noise and wind noise when I accelerate so...
please help. I have a baby and i'm wondering if i should just get another car as soon as i pay this one off.