Hi Im looking for some help here. Upon start up the engine will warm up and i notice a shaking/coughing/....misfire slight feel to the car but more noticeable when put in to gear reverse/drive then the rpm gauge will start to jump slightly and you can hear the coughing sound out the tail pipe and aswell with the jumpy motion of the car but if i turn the ac on it will regulate the feel somewhat but you can still feel it. When i drive the car it drives fine until i come to a complete stop and the coughing returns. Theres forsure a big noticeable amount of gas smell comming from the exhaust.
NOTE: Recently i did a whole timing job with OEM parts and upgraded cast iron tensiones, machined heads new camshafts, lifters, roller followers, vct solenoids, new oil melling pump high output , fuel injectors motorcraft less than a year old, new throttle body, new maf sensor which is reading 9g/s at idle which could be from 800 to 550 when it warms up fully. Have a cold air intake and i washed the filter while i was working on the car, delete muffle aswell but dont see why would this affect the way its happening and also it wasnt happening before when i delete it about a year ago. Sparkplugs are less than a year old and cleaned em up before installing them after timing job, new motorcraft coils, new gas filter, fuel pump about a year old, new fuel pressure regulator which goes up in the gas tank,new pulleys, water pump i mean everything got replace.
Even the o2 sensors which i keep getting the p0420 but the cats where replace about a year ago which i did bought those from ebay and im reading in the short term between -3 and 3 in both banks but long fuel trim in bank one staying around -3 or -0.40 on bank 1 and -7 or -9 on bank 2 and goes down as i accelerate not much but maybe around -5.
ALSO i get misfires randomly in cylinder 1,3, 5, sometimes om the others it really varies and they happen at low rpm between 450 and 550 as its stated in my Forscan. So i really dont know what else to do to fix this issue i guessing is running rich but can figure out what is the cause for this becuase if turnings the ac on kind of regulates the issue i would of thought that it would get worse sinse the compressor requires more fuel, so how i can still smell the strong gas fumes out the exhaust but just want to be able to fix this so i can finally have it running how its supposed. Ill will appreciate big time any help.