I have a 98 passport that stars up fine when its cold,but runs rough untill it warms up.Then it idles okay but it still misses when accelerated.Also once its warm I have to give it gas to get it 2 start.Throws a po300 code, and a code for throttle position sensor,also for o2 sensor heater bank 1.I have replaced the spark plugs with ngk,new egr valve,new o2 sensor(which stopped the o2 heater code),new trottle position sensor(which still throws a code),new fuel filter,pcv valve,mass airflow sensor,temp coolant sensor,air intake sensor,timing belt,and catylactic converters.Still runs badly.I've noticed I can unplug the three fuel injector plugs or coil pack plugs on the passenger side and it runs smoother untill you drive it down the road,unplug drivers side and it sounds like it is going 2 blow up.Coil packs are good also.Passed compression test with flying colors, and coolant system test,and fuel pressure test.I've even tried replacing computer(ignition control module is built in)with no change.Anyone with these problems?Suggestions greatly appreciated cause I'm out a grand with no luck or any mechanics with any ideas left.Also it has 146000 miles with 3.2 and 2 wheel drive auto.

intake manifold gasket. read up in the faq's