Q: I religiously read your Sunday newspaper column right after Dilbert. I keep getting emails about EcoMax, which appears to be a plug-in device promising 15-35% less gas consumption. Is this a viable $49.95 investment? M.S., Valparaiso, Indiana A: I am glad that Dilbert shares the column with you. Do you piously read it while in church? Too-amazing-to-believe fuel saving devices are the work of the devil. Avoid the temptation. Q: In Chicago and probably elsewhere, they are stealing catalytic converters. Is there any low-cost way to put something around them to secure or deter? I leave my Hond…