It coughs & spedders ONLY WHEN COLD after 10-mins or so it runs like new. It only does it when parked or at a red light. When driving at speed it's perfect "you know what I mean". Plugs are new & checked. I think it's the O2 sensor, with codes PO 171 &174 & 300. If it were a vac leak I think it would run poor all the time, right?
Not true. As the throttle plate opens, vacuum transfers from below the plate to above. A vacuum leak would be hardly noticeable at normal speed driving, most pronounced at idle. You're too lean on bank 1 and 2 causing the P0300 random misfire. Almost certainly a vacuum leak at the intake manifold.
"you know what I mean"
I'm sorry- I'm lost. {black}:idontknow:
P0171 and P0174 means that both banks 1 and 2 are running too lean (too much air and not enough fuel). P0300 means that you have a random misfire. You did mention vacuum leak- check for that first. If there is none, check the fuel injectors.
That's probably because as the engine warms up and the metal parts expand, the vacuum leak seals up, allowing for a smooth idle. When it's cold and the metal has contracted, the vacuum leak opens up. It doesn't take much.
AT IDLE, IN DRIVE OR PARK IT RUNS REAL GOOD AFTER 10-MINS & THE REST OF DAY "PRETTY-MUCH".