I have just purchased a 1999 civic for my duaghter. As soon as it was off the lot the ck eng light came on. (code 0420) I've done all the research on the internet. I use SNAP ON Motis at my work and am pretty proficient with it at the graphing scope level. I know what a bad O2 sensor signal would look like but what would bad Cat efficiency look like. I have the techinal tools and skill so I should be able to discern between bad cat or bad o2.I know that typicaly post cat o2 signal is useally flat.I also know to ck all my prelim stuff up stream. Feel free to be as techinal as you like. Sorry for the crappy $5.00 donation if this works out I will defiantly make it worth while in the future. I know what experience is worth!!!!!
Dec 18, 2010 at 5:52 PM