Hi i have a 03 dakota 3.9 auto the problem is all of a sudden the engine will not rev up normally i couldnt get it to go faster than maybe 30 km starts good idles fairly good and there is some sort of intermittent rattle cant really tell where its coming from ..i was hitting the catalytic conv it sounded like something was banging inside not like marbles but something solid banging any ideas a mechanic said maybe a fuel pump? also im not sure but there dosent seam to be alot of exhaust coming out but then its a duel exhaust i just got this truck so im not to familiar with it . even in neutral or park it won,t rev up well or hold rpm i get it up to 2000 rpm then it starts to fall.Thanks

 

check the fuel pressure a cheap easy way to find out if it is the fuel pump or not.

 

Hi just checked fuel pressure with key on 45psi with truck running 50psi very little bleed down so can i assume the fuel pump is good ? if so next i think is the cat when i bang on the cat there does seem to be loose stuff in there can a bad cat cause these symptoms Thanks

 

Sounds like it to me>>>>????

 

so i cut open the cat and the honey comb was broken so i cleaned it all out then welded the piece back back on temporary should i replace the cat with a new one which i all ready have or i could just use the old one gutted i do understand about the pollution aspect