2005 Scion tC acceleration problem
 

Hello,

this is my first thread on this website, however I am very much aware of this website as it helped me alot in the past, and i would just like to thank everyone on this website for their help. Anyways, I would like to start off with where it all began. my car was running perfect, and then i made the mistake of taking my car to Walmart for an oil change. They changed my oil and whatever, after pulling out of the Walmart shop i didn't notice anything not normal, however a couple of blocks down my car started smoking really bad, so i was forced to stop the smoke did not clear, and i figured it was an electric fire, so i disconnected the battery and left it that way for the whole night. next morning i arrived and realized that the dumb Walmart worker left a rag on a wire which burnt. at the time i didn't know that you had to reset the ecu after disconnecting the battery so i just drove on. I began to realize a low rpm idle (650-750), and a horrible shudder at stops. after some research on this wonderful website, some suggested that my throttle body and MAF need to be cleaned, so i did it and properly reset the ecu. the shudder seemed to go away, however the low rpm remained. My car didn't drive weird or anything it was just the idle. However when i decided to clean up the MAF, my car went crazy afterwards, I have began to notice horrible acceleration under 4k rpm, and a slight shiver when cruising on highway speeds. I have ready several posts that said it might be spark plugs, so i also changed them.Things to note: I have a check engine light: P0420, and my car has 196k on it. I am all out of ideas and would appreciate any help

Thank you in advance

Not going to talk about the walmart oil change. Check every vacuum hose and wire that may have been in contact with the fire and verify it is clean and undamaged. But from what you're saying it sounds like the worst performance was after you cleaned the MAF?

Yes for the most part, I have been reading several symptoms that I'm experiencing and some lead to a bad cat or a bad o2 which I'm hoping to replace in the future.