Car runs great...but when i start it in the morning it seems it does not have gas power and it may shut down.As soon as i step on gas and it gets flow it runs good...When i am at intersection it stumbles when i press gas,i just dont have the power to take the road when someone is approaching me which is dangerous.I took it on computer reading and they told me it mite be a catalyst converter.Do you know what could be the problem and $$$?