If you are willing to try a temporary fix such as a fuel additive, and this still doesn't work... If you are still after that temporary fix, then get a tank full of CO2 and hook it to where the oxygen sensor goes. When the inspection guy puts the probe in your exhaust pipe, then have a passenger open the valve on the CO2 tank. No, seriously... First, before you do anything make sure that your DeLorean was fully warmed up before it was inspected. This is probably not likely in your case, but it would be silly to replace your catalytic converter if it only failed the test because it wasn't fully warmed-up. The hotter a catalytic converter is, the more effectively it works. After all, it was only by 200 points that your car failed. Going back on a hotter day (or just any day) may give you the points needed to pass. On the second time through, a favorable contributing factor may be more significant. Walt Tampa, FL