This 2003 Toyota Echo ran great for several days. No leaks, no coolant leak. No engine lights. 213k Miles automatic.

It started acting weird under acceleration. Very subtle. But drove fine. Then one day I slammed on acceleration and was pretty noticable delay in engaging in transmission. But didn't really sound like it shifted hard or slip.

So one day I took the spark plugs out and checked em, they were ok. And put them back in. Also took battery out that night for what seemed like the first time that battery had been taken out in years. Then put it back in 

So tried to drive off that night. And it would move if I just tapped on the accelerator but if I put more force on pedal would just heavily bog out. 

Checked under hood nothing was unplugged. I'm confused how this could happen out of nowhere. My friend checked the coil packs, they were fine. Checked fuel injectors one didnt look so good but friend tested it and they were all fine. 

My friend straight piped it a couple days before this happened. Idk if that has anything to do with it. There is a small exhaust leak he needs to fix.

We thinking maybe throttle sensor but isn't usually code for that. I moved over sensor from my vibe and no improvement but friend said I needed to adjust it. I didn't do that, idk how to do that 

So thinking of maybe if I put it back on and adjust maybe will work. 

When my friend was daignosing it he saw it had a clynder 1 misfire and a air sensor I think. But those went away shortly after.