Hi Scotty, been a long time viewer of your channel thank you for all your hard work and dedication. I just purchased a 2007 Nissan versa with a 1.8 liter n/a engine and a 6 speed manual transmission. I bought it for $700 from my neighbor and I quickly learned why he sold it to me so Cheap. It only has 150,00 miles but has a hard code for p0420 I managed to still get it to pass emissions inspection by clearing the code and and driving to the emissions station really quick. It has a few issues, I don't think the catalytic converter is clogged because it has good power and is flowing out the back very well. I was told by my mechanic that most often in those Nissans it is a vacuum leak. But we hooked up the smoke machine and NOTHING can be seen. It's driving me crazy. The O2 sensors seem to be operating as they should. It also has another issue, in 5th and 6th gear it's whining at about 2-3000 rpm, I was told this was normal by my mechanic friend who worked for Nissan previously. I just wanted a second opinion on this, and thought who better than to ask the man, the myth, the legend himself. Thanks Scotty!