bull727

whats up fellow lexus owners....i had my 400 for a month now and i had trouble with it ever since i bought it. my first question what is the recommended cold crank for this on the battery. i was sold a 500cc by idiots at autozone and my car died 2 times in 2 weeks. so after getting another alt and battery so far so good i notice a big difference with a 750cc battery. like my seatbelts going back in lol. but lot of ppl teling me i need a bigger battery still. so i want to know whats the size some of you people have in yours. im a delivery driver at the moment and i believe the way i use my car i may need a bigger battery still. next question engine light been on since i got the car. but a week after i got the car everytime the light comes on my car jerks and from there a lot of studdering,hesitation or whatever term u want to use is going on. once i go past 50mph it stops. under 55 it starts again and every time i slow down or have to stop i does it until i hit a high speed. i know best thing would be to get a scan but i was wondering is there somebody who could play by ear who could give me an idea on what it is. other than that i like the car but i havent enjoyed it yet u could say.