2001 GMC Yukon xl SLT 1500 4wd 5.3L New ECM, Still Multiple DTC's Starts but Won't Run

Handy Man1 · May 5, 2022

Help!! Multiple DTC's!! 2001 5.3l Gmc Yukon XL SLT 1500 4wd w 190,000 mi
Originally Unable to get SMOG Cert due to SES MIL light illum. (or Inc. Cat Monitor)
Currently has P0101, P0155, P0300, & p0756 (after replacing ECM, Coils, Wires, & Plugs)
Previously had P0171 that wouldn't go away ( the following has transpired over approx last 18 mo's)
Initially the service engine soon light (MIL) came on found P0171 code.
Erased code, Cat Monitor won't complete before another stored P0171 DTC illum's MIL
B1 short fuel trim varied from -20 to +25 but typical was -5 to +5,
B1 long fuel trim rarely went below +25 and up to +40 at times
B2 short fuel trim avg. -2.5 to +2.5, long fuel trim avg -14.8 to +15,
Note; after each repair I would erase codes and do GM drive cycle. all monitors would Complete
except the Cat monitor then mil illum w p0171
since then have replaced the following:
O2 Sensors B1S1 & B1S2 (p0171 still)
New fuel pump & filter, Press 48 psi, pulse 39-40psi (p0171 still)
Vacuum leak test (no leaks detected)
New air fltr, Mass Air Flow Snsr, Battery, Pos & Neg Batt cables, Alternator, Cleaned all obvious Ground's (p0171 still)
Smoke press. test intake, found very small intermittent wisps around intake #3 cyl
Replaced Intake manifold gaskets, (p0171 still) (Also new water pump, Radiator, Oil & Fltr,(unrelated to drivbility issues)
No codes but still Cat monitor won't complete and after numerous drive cycles
and intermittent MIL (it would go off by itself) found intermittent p0171 usually pending
but stored when MIL stayed illum) also engine would intermittently sputter and hickup at higher revs on freeway with blinking then steady then no MIL (p0171 at times stored usually pending & sometimes P0300 pending, MIL intrmtntly on & off by itself other than that engine performance was pretty good with no MIL's for days / weeks at a time. (still no Smog cert. Cat monitor doesn't fail it just won't complete. Then.....
Suddenly started running really rough, coughing, sputtering, no power, no throttle response, (no rpm's except in P or N) or eventually (3-10 sec's w thrtl deprssd) when manually placed in L1, upon manual shift to higher gear at higher rpm 3k-5k rpm drop and cough, and frequently stall when shifted even at higher revs.
MIL constantly Flashing or On steady. Found Numerous DTC's Stored and Pending,
Lean Bank 1, Multiple/Random Cylinder Misfire, MAF out of Range, EGR oor, Shift Solenoid Malfunction, Throttle Position Sensor Error, O2 Sensor oor B1S2 & B2S2, Evap Rec. Systm Mlfnctn, VSS Error,
Removed ECM and after visual inspection (connectors and visible wiring, smell, etc...) Reinstalled.
Running like ****** after a minute or two, Idles fine but a little rough. Multiple DTC's again
Decided at this point that the ECM must be faulty.
Replaced ECM w/ Remanufactured and Pre Programmed ECM (matched to orig VIN prgrming)
Engine crank but won't run for more than .5 sec.
After sorting out V.A.S. issues (key relearn) engine starts & barely runs w blinking MIL. P0300 DTC
Replace Coils, Plugs, and Wires. Reset MIL, Starts and runs OK? within first mile (minute) starts sputtering. gets worse, within 2 miles (or approx 2-3mins) no throttle response (xcept in N or P), fuel light illum & gauge sporadicly goes to E then back to 1/4, but confirmed at least 1/4 tank, no power, seems to occur or get worse as engine warms up. cold start engine runs and drives OK? for about less than 5 min's or under 2 miles
then it sputters and dies. cranks but wont run with DTC's P0101, P0155, P0300, P0756.
Starts and drives (when cold?) but not for very long or far.
Kinda at a loss here as far as what to check next? I'm thinking wiring, Grounding problem?
My scan tool is limited to OBDII emissions only so not really much help.
Any suggestions, advice, or Tech info will be greatly appreciated Thx

Niners 365 · May 5, 2022

I noticed you replaced everything electrical but one thing. By chance have you looked at your distributor? If that is worn and burned out, it will litterally cause all your idle, firing, rough, and dying out. Also you state a code P0710 or something similar for the cat. Are you talking the catalytic converter? Not sure why you replaced the ECM for that? Dis you check the sensor for that back thier?

Also O2nsensors when they go out will cause rough, jerking idles. My wifes Jeep and my 2003 S10 did exactly that when those went out.

Handy Man1 · May 6, 2022

10 hours ago, Niners 365 said:

I noticed you replaced everything electrical but one thing. By chance have you looked at your distributor? If that is worn and burned out, it will litterally cause all your idle, firing, rough, and dying out. Also you state a code P0710 or something similar for the cat. Are you talking the catalytic converter? Not sure why you replaced the ECM for that? Dis you check the sensor for that back thier?

Also O2nsensors when they go out will cause rough, jerking idles. My wifes Jeep and my 2003 S10 did exactly that when those went out.

WELL fer starters there Niners 356, the Distributor on this yr. mk. & mdl vehicle is an extremely difficult type to do any repairs to. And as far as it being worn out and replacing it? That is just not really a viable option in this situation. Reason being that locating and actually acquiring a Distributor that could be installed and work on MY particular stock 2001 GM 5.3L Vortec V8 engine, would literally be almost impossible to accomplish! It would be Way too time consuming, not even slightly financially feasible, and the whole thing is way beyond the scope of my knowledge, outside the realm of my available resources, and definitely requiring talents and abilities that are not within my Skills set! Now then, with that being said, Thank you winers 536, for taking the time to respond to my post. And for being kind enough to offer me a bit (actually, several bits) of your invaluable knowledge and expertise. Now I will Assume, that you did this with the assumptions that, (1) I was actually lacking some or all of the information that you provided, (2) that I needed it! and you would be helping me by providing it, and (3) by me now having that information, you would be providing me with some clarity to that part of my world, in which you thought you saw confusion, and finally (4th), that your Two Cents worth (literally 2c <w 1 T>) of an opinion, in your mind, would be of some useful value or an Asset to me in my current quest in the allocation and subsequent acquisition of RELEVANT, ACCURATE, and USEFUL INFORMATION on the subject of diagnosing my truck.

Miners 653, Can you refer me to a Qualified Mechanic that would be able to repair or replace the DISTRIBUTOR on my 2001 GMC 5.3L Vortec V8 engine that won't take too long or charge too much to do it? Thx Again, I'll be anxiously awaiting your response.

shakenfake · May 6, 2022

You don't even have a distributor....

txab · May 6, 2022

3 hours ago, Handy Man1 said:

WELL fer starters there Niners 356, the Distributor on this yr. mk. & mdl vehicle is an extremely difficult type to do any repairs to. And as far as it being worn out and replacing it? That is just not really a viable option in this situation. Reason being that locating and actually acquiring a Distributor that could be installed and work on MY particular stock 2001 GM 5.3L Vortec V8 engine, would literally be almost impossible to accomplish! It would be Way too time consuming, not even slightly financially feasible, and the whole thing is way beyond the scope of my knowledge, outside the realm of my available resources, and definitely requiring talents and abilities that are not within my Skills set! Now then, with that being said, Thank you winers 536, for taking the time to respond to my post. And for being kind enough to offer me a bit (actually, several bits) of your invaluable knowledge and expertise. Now I will Assume, that you did this with the assumptions that, (1) I was actually lacking some or all of the information that you provided, (2) that I needed it! and you would be helping me by providing it, and (3) by me now having that information, you would be providing me with some clarity to that part of my world, in which you thought you saw confusion, and finally (4th), that your Two Cents worth (literally 2c <w 1 T>) of an opinion, in your mind, would be of some useful value or an Asset to me in my current quest in the allocation and subsequent acquisition of RELEVANT, ACCURATE, and USEFUL INFORMATION on the subject of diagnosing my truck.

Miners 653, Can you refer me to a Qualified Mechanic that would be able to repair or replace the DISTRIBUTOR on my 2001 GMC 5.3L Vortec V8 engine that won't take too long or charge too much to do it? Thx Again, I'll be anxiously awaiting your response.

Please lose your attitude, if you want help on the site. So the guy made a mistake, lay off.

Niners 365 · May 6, 2022

Well for starters, I was not aware that era make and model dont have one. My 2003 S10 4.3 vortec has one candy man 101, that is electronically controlled. All you have to do is replace the distributer head when it burns out.

Mine will do exactly the same as yours does when it burns out. Just offered an idea. Your obvious expertise on your vehicle is far superior to anyone else's cant understand why you would be asking for help. Have a good one.