Brief history , 3 yrs ago did a performance exhaust with Cat delete , K&N intake system , coil packs and OEM NGK plugs , never threw a code once . 2 months ago changed plugs with same NGK plugs drove for 20 minutes car ran great . hour later went to drive home noticed a miss fire under 1500 RPM only and when I pull up to a light and after 10 seconds at idle it starts to miss fire ,code P0300 came up when I got home, being an old car I replaced Fuel pump assembly and fuel injectors , problem is less but not gone and over 3000 RPM car runs the best it has ever .Did a cleaning of the EGR and intake manifold look very clean . I tested the IAC and TPS sensor with meter and it checks out good .5 volt at idle , left the TPS unplugged and the idle problem is gone but have to use the manual shifting . Computer might be using previous known values since sensor is unplugged but it runs perfect except for shifting . Does anyone have any ideas .