Hesitation and no power

[slb21f67]

i have a 97 C3500 5.7. Yesterday started driving and after around 3 minutes it started running a little rough and quickly got worse. Check engine light came on as well. Before I could get it back home lost all power while in gear and had to tow. Truck would run at idle and will rev in neutral, but put in gear and bogs down and barely move.
Today.. codes were O2 sensor bank 2 sensor 1 and sensor 2 no activity. I replaced them both today and the check engine light is gone, erased codes and they did not come back, though no change in performance. I took a video for the sound but seems mp4 will not upload. When pressing the gas there is a hesitation with a heavier, thumpier sound, most notable at low rpm and takes slightly longer than normal to reach higher rpm.
Background.. 3 months ago changed fuel pump, fuel filter, spark plugs and wires, rotor cap. Today the fuel pressure is 52 at idle and 58 at higher rpm. I have not driven the truck for about a week, and during this time changed out the A/C compressor and accumulator, no issues. I thought perhaps I knocked something loose and have been all over engine but can't find anything that looks off.
Attached is my current scan info at idle. I have browsed several threads but haven't found anything yet that stood out, if anyone can point me to where I should troubleshoot next.. much appreciated.

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[docstoy]

Fuel pressure koeo ? Does it hold pressure ? O2 sensor fuses good ? Any modifications to truck or everything stock ?

 

[slb21f67]

The fuel pressure is steady with the engine off, at least for a short bit, I haven't checked for an extended time. I did not know there were fuses for the 02 sensors but will look into that, however I am getting a reading from the O2 sensors. The truck is standard except for a service body and second gas tank which i have not used for many years.

 

[docstoy]

What is fuel pressure koeo ? Have you lookedin fuel and emissions manual about fuel system, if you haven't they are available free, go to sticky threads above look for thread titled 88-98 service manuals , it will tell you more in a few minutes than I could type all night. HO2's have fuses for the heaters which helps with faster closed loop operation of computer system and emissions. Keep us informed and best of luck

 

[GoToGuy]

It heats up sensor faster to reduce emissions. But after the engine is warm , there operating normally as seen on scanner.
Since it happened after you worked ( touched ) on it. Recheck anything you touched , replaced, or moved.

 

[slb21f67]

What is fuel pressure koeo ? Have you lookedin fuel and emissions manual about fuel system, if you haven't they are available free, go to sticky threads above look for thread titled 88-98 service manuals , it will tell you more in a few minutes than I could type all night. HO2's have fuses for the heaters which helps with faster closed loop operation of computer system and emissions. Keep us informed and best of luck

Thanks. koeo after 15 minutes dropped to 48, after 1 hour 32 psi. The O2 fuse good. I have been reading through the service manual as you recommended and will continue to do so.

 

[1998_K1500_Sub]

Bank 1 fuel trim looks funky to me...

but nobody else said anything about it so...

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Coolant temp shows 66C --> 150F.

If the engine's been running and is supposed to be at operating temp, it's not. FWIW.

 

[slb21f67]

It heats up sensor faster to reduce emissions. But after the engine is warm , there operating normally as seen on scanner.
Since it happened after you worked ( touched ) on it. Recheck anything you touched , replaced, or moved.

Thanks. I spent a few hours today checking everything that could have been bumped and haven't found it yet. Ran engine with a variety of sensors unplugged and get the codes for each, but no change in performance. I have read people saying clogged cat. i am also suspecting fuel injectors, just not sure if either of those would cause the problems i experienced that escalated from first hint of problem to complete loss of power in about 10 minutes of driving time.

 

[GoToGuy]

Plugged, or non functional cat converter would or should give you a malfunction code. A degredation in function. Your sensors in no. 2 position , after cat are reading correctly. The way to check is measure how back pressure in exhaust before cat.

 

[slb21f67]

Bank 1 fuel trim looks funky to me...

but nobody else said anything about it so...

You must be registered for see images attach

Coolant temp shows 66C --> 150F.

If the engine's been running and is supposed to be at operating temp, it's not. FWIW.

Thanks for that. The engine had not been on for long so hadn't reached temperature yet. I don't understand the fuel trim numbers yet but will read up on that next. If you don't mind, if the fuel trim readings are off, is there a primary culprit?