Okay, I have quite a few codes. So here is my description. I have a 2000 Gt. and for about two months its had I weird idle. Like it would drop down to 500rpms etc and sometimes stall. Well then it started jumping up and down on a cold start. This would be random to. Some days it would be fine others it wouldnt. Then I started to feel a hesitation at cruising speeds and it really confised me. WOT it would run like the beast she is. The other morning the check engine light was blinking. and i know it was a misfire. Seems that cylinder 3 misfired. pulled the plug out. plug looked good. they are only a few months old anyways. So I ordered a coil. Waiting for it to come in and hopefully that fixes the misfire. But at the same time I havent had the engine light blink anymore. It just stays on. Here are the codes it pulled. P0455, P0401 , P1150, P0174, P0303. I know this is long and I may be asking a lot. but if someone could explain these codes better to me and tell me how to fix them I will greatly appreciate it. Another thing I have noticed is Since I put my Catless x pipe on when I start it up and let it idle for a few white smoke comes out the exhaust? Any info on that would be appreciated as well. I just wanna get my Gt Back as she should be with no CEL!