2000 Toyota corolla power loss

My thoughts are you shouldn't drive a vehicle when it is having problems like that and YOU shouldn't touch or work on cars .

P0125 is a coolant temp issue, low coolant, bad ECT, etc. P0135,P0141 are the O2 sensor detecting an issue. It could be wiring or other drivability problems. How many miles on your car? I'd get a shop to diagnose this one for you, too many things going on, and no reason for you to guess and swap parts that don't need replacing. Good Luck.

It'a got 185,000. It's been very well maintained and still runs great. Gotta love Toyota. And I wondered about the oxygen sensors, I replaced them not to long ago because I was getting a PO420 code, and obviously the code makes them very suspect but I didn't think that an o2 sensor could cause it to go into limp mode like that. A lose of efficiency absolutely, that's one of the bigger reasons I replaced them in the first place, but I still have the old ones. They only seemed to throw a code so if I put them back on and the problem seems to go away maybe I return the new ones and swap them out for better ones. That way at least the troubleshooting is free. I live in a smaller town and honestly the times I have brought cars to be troubleshooted they charged me for a worse diagnostic than I had and they proved to be off when we finally fixed the issue. So I guess start there and if I can't figure it out with something simple I'll just need to find a mechanic that is good at troubleshooting and doesn't charge an arm and a leg to do it.

I think I may have missed something. The "car's level of care"? As mentioned earlier the car has been very well maintained from oil changes, to transmission fluid changes, to sensors throwing codes. Cars in my family tend to go 300,000-380,000 miles because we our "level of car care" If you mean driving it home instead of towing it to the nearest mechanics shop, well I can't do much about that. After towing ($300+) and then paying a mechanic for a diagnose($200-$500) I can't really afford that...,especially for a $1800 car. But good to know about the O2 sensors. I put the old ones on today and had the battery disconnected overnight to reset the limp mode and so far it seems to be back to normal. I won't want to go long distance until I get a few hundred miles on it I think because it took a couple hundred after I replaced the O2 sensors before they started giving me problems. Thank you for the advice :-)

Check to make sure you didn't switch it by mistake to (manual) stick shift. Just push the shifter to the right side (towards passenger side) and it should put it back into automatic.