Sharing some information with the forum… Two weeks ago I plugged my Durametric system into my 01 and it showed three codes in memory but no CEL, they were P0430 (CAT Conversion Bank 2 Exceeds Limit), P0410 (Secondary Air Injection Cylinder 1-3), and P1411 (Secondary Air Injection Cylinder 4-6). I cleaned my MAF sensor, didn’t think it would really do anything because I cleaned it a couple months ago, but I had to try (I have never replaced my MAF sensor so it’s always suspect). I came close to buying a new MAF sensor but had to try a couple things first. Checked the system for alarms a couple days later and all three alarm codes were back. After a little more research, and reading causes for these alarms, I ordered a new gas cap (I have never replaced the gas cap since owning the vehicle). Installed the new gas cap last week, check for alarms today, all GREEN indicators, and no alarms! See photo below, the rubber seal on the old gas cap has many cracks preventing a tight seal, probably a major vacuum leak.