Hey y'all. P0420 on my 2007 Gen 2 found at emissions testing in Illinois. Aftermarket cat was installed after mine was stolen about 2 years ago. If I installed an O2 sensor extender and went back to emissions testing, do we think that's something they'd look for? My understanding is using one to pass emissions is illegal. I also understand that lots of folks do it. If I had known about it, I would have installed one prior to my 1st test. But I figure that they'd keep an eye out for quick fixes. Then agaaaaain, these are gov't employees that wouldn't do any extra detective work if it wasn't required of them. My car's got 300K+ miles, so it's not long for this world, and not worth spending too much money fixing. Ehh?