ok so ive had a bad engine miss under load for sometime now on my 98 4.6......the engine code was throwing catalyst flow insuffiecient on bank 1.....so i pulled the cat and gutted just to see if that was the problem.....it wasnt. So i proceded to change the plugs with OE replacement plugs, and i put MSD super conductor wires and i even replaced one coil pack. still misses. Now when it rains the truck runs really bad, to the point i almost cant drive it. now when i welded the cat back on, i couldnt get the top very well, i wasnt worried about it cause im replacin the cat soon anyway, so it has a exhaust leak, but what im thinking now, is that my problem is the 02 sensor behind bank 1. Now if the O2 sensor is bad, would it throw the flow insuffient code or would it throw its own seperate code?? cause i think when it rains, water comes in that exhaust leak and hits the 02 sensor and that makes it run even worse. does all this make sense or am i goin in the complete wrong direction. somebody help me here!!

 

..the engine code was throwing catalyst flow insuffiecient on bank 1.....

I think we would be able to help you better if you post the actual code numbers.

 

are you sure its not EGR flow?
DPFE sensor?!?!

 

i dont know the actual code, i had it read at auto zone and the guy just told me catalyst flow insufficient on bank 1. And also i forgot to say that when it rains and the truck runs bad........the check engine light flashes?