MDTAHOE

Po 171 and 174 are lean codes. 1345 is most likely being set due to backfire

MDTAHOE

Clogged fuel filter is extremely common on these trucks and would do exactly what you describe

slw210

No problem, glad you liked it.

Any more info on your problem?

jhargis1

Keeps getting better. Pulled the intake. Pulled the (2) pieces aparts a found the leads for the nozzles had fried when the engine backfired. All the internal parts for the injection will have to be replaced. Over 3 bills.

MDTAHOE

Could be the cause of your whole problem. Also very common for that system to fail it has actually been updated

jhargis1

UPDATE- replaced the injection system with updated version. replaced all (3) O2 sensors. Started up and seemed to run smooth for about 2 minutes (check engine light was off), then started running rough (check engine light came on) ran the code and got a P0340. Here is the diagnostic with it-
<TABLE class=DiagnosticReportDataList cellSpacing=0 cellPadding=0><TBODY><TR class=Content><TH style="WIDTH: 150px" vAlign=top noWrap align=left>P0340</TH><TD vAlign=top><TABLE border=0 cellSpacing=0 cellPadding=0 width="100%"><TBODY><TR><TD style="PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; VERTICAL-ALIGN: top; PADDING-TOP: 0px" vAlign=top align=left>CMP Sensor Circuit Malfunction</TD><TD style="TEXT-ALIGN: right; PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP: 0px" vAlign=top></TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE>
<TABLE class=DataList border=0 cellSpacing=2 cellPadding=0 width="100%"><TBODY><TR><TD vAlign=top>Conditions For Setting This Code: Engine started, engine running, and the PCM did not detect any CMP sensor (Hall Effect) pulses at least once during 2 complete crankshaft revolutions during the CCM test.

</TD></TR><TR><TD vAlign=top>Possible Causes: * CMP sensor signal circuit is open or shorted to ground
* CMP sensor VREF circuit is open between sensor and PCM
* CMP sensor ground (Low Reference) circuit is open
* CMP sensor is damaged or it failed (check the reluctor wheel)
* PCM has failed
* TSB 02-06-04-043 contains a repair procedure for this code

</TD></TR></TBODY></TABLE>

GDELGADO

any more info on your truck.. i have a similar case just wondering..

jhargis1

The cam sensor at the distributor was off. Not sure how. I marked the distributor location and the rotor location, but the timing was still off. I ended up taking it to a friends shop. He put it on the computer, set the timing and now I'm good to go. The loose timing chain and intake leaks were the original culprits. Popping back through the manifold burned up the injection.