on my 07 IS250, those codes popped up a few weeks ago, I cleared them and they pretty much came back on. Then I changed the MAF sensor, and it was "fine/fixed" for a few weeks and about 122miles. Now came back on again. How can I tell if it's the knock sensor itself, the wiring connector, or something that trips those codes? My dad was driving it and said that he smelled a faint burning as soon as I came on the first time a few weeks ago and again today.