I just bought a 99 5.9l 4x4 and it has started to give me trouble, it has 156000km on it . It first started to loose power so I took it out of od to get the thing home, over the next 6hs of driving it got worse, the rpms would drop right off and eventually started to blow oout black smoke (flooding itself) the next day I started the truck and it worked fine for months, however I drove my truck over a curb that was covered in snow ( it hit pretty hard), suddenly my old problem has come back even worse. I changed the plug wires checked rotor and cap tested the AIT sensor. Please help

 

def check your pre cat o2 sensor. or senosrs if you have two. the bump may have knocked a wiring harness loose. or they may just be bad. or get an obd2 code scanner if your engine light is on. they sell em for 120 now i think it is at advanced auto. i paid 160 for mine i shoulda just waited. their web site is www.partsamerica.com .