2003 2500 hd 6.0 Help

[Rich Davis]

Ok, so I bought the truck off father inlaw knowing it had "a few" issues. well after doing full tune up, coil packs plugs, wires. it threw several codes. too lean bank one o2 sensor , knock sensor. so I began fixing it one by one. Now I have 2 new o2 sensors. new crank position sensor, new knock sensors, new cam position sensor, new maf, new map sensors. I am still getting a p0300 multiple cylinder misfire and knock sensor bank 1 low voltage. I did compression leak down test and all held well. Did fuel pressure test also good. cleaned and checked all injectors. I have checked for  any vacuume leaks and nothing I do will help. It will throw those 2 codes after getting into the throttle. The truck has no power

[davester]

The knock sensor could be a wiring or connection problem.

 

It's common for the 6.0's to break off exhaust manifold bolts.  Check if all the bolts are there, and extract/replace any missing ones (and perhaps install new exhaust gaskets).  If enough are missing, then clean air can get into the exhaust, and cause the O2 sensors to read a lean condition, so the ecm will dump in more fuel (but may not throw a code).

[05lq4]

Be sure to get 'genuine' oem parts for the knock sensors and their wire harness. I have never heard a good thing about the cheap ones. 

[Rich Davis]

Yeah I found a crack at the weld of one of the catalytic converters. I just fixed the rear when adding duel magna flows. It's definitely cracked bad now. Added some muffler seal by Jb in the meantime til I can get it welded right. Thanks for the input lets me know I'm on the right track