I'm sorry if this is the wrong forum but I think it's the right one. My SES light comes on only at WOT and usually goes off after a while of normal driving. I had the code checked and it read low voltage in all 4 o2s. I still get 20+mpg but the car's definately lacking power. Is it possible that it's something in the charging system and not the o2s? I don't wanna buy parts I don't need. Also, what is the best place to buy o2s? I don't have LTs and won't for a while so I don't think I need sims.