When I initially turn the key it seems like I have a dead battery. If I hold the key it slowly starts to crank and then will start if I feather the gas pedal. When I come to a stop or let it go down to idle it will stop running, again, unless I continually press the gas pedal. After a while it seems to get better and will idle. I changed all 4 oxygen sensors (Cali emissions) and put injector cleaner in my last refill. I am worried I am doing more damage but don't know where to begin. No fault codes show on my reader. Has anyone else experiences this?