Hi I'm having a problem with my 99 corolla when I bought the car it was working fine and then the car started sputtering and wouldn't want to accelerate when I floored it the car started working okay again it started working fine after a few weeks and only recently it started doing it again one day I was driving and then my power started dying in and outside of the car and when I floored it all the power started working again and then it died again so I got a new battery started working perfect but died 2 hours later jumped it and turned on but the moment I took it off it died again so I figured that it might be the alternator so I took it off and got it tested and they said it was working perfect so I don't know what it could be so if anyone can help me I would appreciate it thank you.