P0300 & P219A codes

ktuck · April 19, 2024

On 4/18/2024 at 8:36 AM, newdude said:

My thinking is you got old stock and could have 2 bad ones.

If the rain can hold off, I'm going to replace the injectors today. I may not finish until tomorrow, I'm an old man now and work much slower! Pulling that intake with a engine that is set back so far, is a real challenge for me. Afterwards I'll post how everything turned out. Meanwhile, fingers crossed.

ktuck · April 22, 2024

Well, my theory did not play out as I had hoped. After replacing the injectors (again), there was no change to the misfires, numbers 2 and 5 still misfiring regularly and number 7 misses occasionally as well. Upon removing the manifold and fuel lines, I did not notice anything incorrectly done from the first injector replacement. I tested all 8 injector wires in each harness and each read the same. No leaks around the hi pressure pump or any of the lines. The only thing of concern I saw was most of the injector tips had brown deposit stains on them...not a bunch of buildup, but a very thin layer of crust. The truck has been driven less than 200 miles since the first injector replacement. that seems like a very short time for that amount of buildup. Oddly, with the high negative fuel trim numbers, the porcelain tips of all the spark plugs appear more lean than rich. So, the consolation prize is that I guess I have effectively eliminated the injectors from the equation. However, P0300 and P219A remain along with the CEL.

I feel like I've simply become a parts changer now and chasing after new theories each time. I was ASE mechanic in the 70s, 80s and 90s, but so much has changed since then and I've been away from the automotive scene for a while. OBD2 was new when I hung up my wrenches professionally. The amount of money I've thrown at this problem has grown to a ridiculous level. If I had known what was coming, I would have cut my losses and wholesaled the truck right off. Now I'm invested so deep in it, I feel I have to see it thru and besides, I still owe 11K on it and that complicates things even more. The only thing I know to do, is go back to the data. My autel scanner shows high LTFT negative trim numbers on each bank, but bank 2 the highest at -33%. Bank 1 is running around -14%. This is the only data showing up which is out of normal range and actually by a good bit. It seems logical to me that if I find and correct the fuel trim numbers, I will be solving the running problem and CEL. That has proven easier said than done. None of the suggested common causes for high negative trim numbers have proven to be the problem. Most have been either eliminated or replaced with no difference, The only exception is the MAF which I have tested and it shows normal function. I've got to be missing something and for the life of me, I don't know what. My latest "theory" is that possibly the misfiring itself is what is causing the high negative LTFT. The two worse misfiring cylinders are 2 and 5. Cyl 2 is clearly misfiring worse than 5 and is on bank 2 which has worse LTFT numbers. Cyl 5 on back 1 which has about half the negative LTFT number bank 2 has. But that may not hold water either as cylinder 7 is misfiring at times and when you add the total misfires of 5 and 7, they are slightly more than cyl 2. Trying to make sense of this, any ideas would be appreciated, thanks.

newdude · April 22, 2024

2 hours ago, ktuck said:

Well, my theory did not play out as I had hoped. After replacing the injectors (again), there was no change to the misfires, numbers 2 and 5 still misfiring regularly and number 7 misses occasionally as well. Upon removing the manifold and fuel lines, I did not notice anything incorrectly done from the first injector replacement. I tested all 8 injector wires in each harness and each read the same. No leaks around the hi pressure pump or any of the lines. The only thing of concern I saw was most of the injector tips had brown deposit stains on them...not a bunch of buildup, but a very thin layer of crust. The truck has been driven less than 200 miles since the first injector replacement. that seems like a very short time for that amount of buildup. Oddly, with the high negative fuel trim numbers, the porcelain tips of all the spark plugs appear more lean than rich. So, the consolation prize is that I guess I have effectively eliminated the injectors from the equation. However, P0300 and P219A remain along with the CEL.

I feel like I've simply become a parts changer now and chasing after new theories each time. I was ASE mechanic in the 70s, 80s and 90s, but so much has changed since then and I've been away from the automotive scene for a while. OBD2 was new when I hung up my wrenches professionally. The amount of money I've thrown at this problem has grown to a ridiculous level. If I had known what was coming, I would have cut my losses and wholesaled the truck right off. Now I'm invested so deep in it, I feel I have to see it thru and besides, I still owe 11K on it and that complicates things even more. The only thing I know to do, is go back to the data. My autel scanner shows high LTFT negative trim numbers on each bank, but bank 2 the highest at -33%. Bank 1 is running around -14%. This is the only data showing up which is out of normal range and actually by a good bit. It seems logical to me that if I find and correct the fuel trim numbers, I will be solving the running problem and CEL. That has proven easier said than done. None of the suggested common causes for high negative trim numbers have proven to be the problem. Most have been either eliminated or replaced with no difference, The only exception is the MAF which I have tested and it shows normal function. I've got to be missing something and for the life of me, I don't know what. My latest "theory" is that possibly the misfiring itself is what is causing the high negative LTFT. The two worse misfiring cylinders are 2 and 5. Cyl 2 is clearly misfiring worse than 5 and is on bank 2 which has worse LTFT numbers. Cyl 5 on back 1 which has about half the negative LTFT number bank 2 has. But that may not hold water either as cylinder 7 is misfiring at times and when you add the total misfires of 5 and 7, they are slightly more than cyl 2. Trying to make sense of this, any ideas would be appreciated, thanks.

DTC P219A - Fuel Trim Cylinder Balance Bank 1

DTC P219A or P219B
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic approach.
Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptor
DTC P219A
Fuel Trim Cylinder Balance Bank 1

DTC P219B
Fuel Trim Cylinder Balance Bank 2

Circuit/System Description
The Fuel Trim Cylinder Balance diagnostic detects a rich or lean cylinder to cylinder air/fuel ratio imbalance. The diagnostic monitors the pre-catalyst heated oxygen sensor (HO2S) signal's frequency and amplitude characteristics by calculating an accumulated voltage over a predetermined sample period. An imbalance is indicated when multiple samples of the accumulated voltage are consistently higher than the desired value.

Conditions for Running the DTC
DTCs P0016, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0122, P0123, P0128, P0201–P0208, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, P0277, P0279, P0280, P0282, P0283, P0300, P0301–P0308, P0340, P0341, P0442, P0455, P0458, P0496, P1248, P1249, P124A, P124B, P124C, P124D, P124E, P124F, P16F3, P2101, P2135, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P216B, P216C, P216E, P216F, P217B, P217C, P217E, or P217F are not set.

The evaporative emission system device control and intrusive diagnostics are not active.
The engine overspeed protection is not active.
The power take-off is not active, if equipped.
The engine is in closed loop status.
The system voltage is greater than 10 V.
The engine coolant temperature is warmer than −20°C (−4°F).
The engine speed is between 800–3,750 RPM.
The mass air flow is between 5–1,000 g/s.
Engine run time is greater than 25 s.
Fuel level is greater than 10% and no fuel level sensor fault is present.
The DTC runs continuously when the above conditions have been met.

Conditions for Setting the DTC
Multiple samples of the pre-catalyst HO2S accumulated voltage are consistently greater than the desired value.

Action Taken When the DTC Sets
DTCs P219A and P219B are Type A DTCs.

Conditions for Clearing the MIL/DTC
DTCs P219A and P219B are Type A DTCs.

Diagnostic Aids
The fuel trim cylinder balance diagnostic is very sensitive to heated oxygen sensor (HO2S) design. A non-OE sensor or an incorrect part number may cause a DTC to set.
Monitoring the misfire current counters, or misfire graph, may help to isolate the cylinder that is causing the condition.
Certain aftermarket air filters may cause a DTC to set.
Certain aftermarket air induction systems or modifications to the air induction system may cause a DTC to set.
Certain aftermarket exhaust system components may cause a DTC to set.

Troubleshooting with a Test Lamp
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Connector Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference
Control Module References for scan tool information

Circuit/System Verification
Ignition ON.
Verify no other DTCs are set.
If any other DTCs are set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.

If no other DTCs are set
Verify DTC P219A or P219B is not set.
If a DTC is set
Refer to Circuit/System Testing.

If no DTC is set
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed in the Freeze Frame/Failure Records data.
Verify DTC P219A or P219B is not set.
If a DTC is set
Refer to Circuit/System Testing.

If no DTC is set
All OK.
Circuit/System Testing
Engine idling, transmission in Park or Neutral, verify the manifold absolute pressure (MAP) sensor parameter is between 19–42 kPa (2.7–6 PSI).
If not within the specified range.
Refer to DTC P0106.

If within the specified range, inspect for the conditions listed below:
Modified, damaged, leaking, or restricted air induction system components.
Improper operation of the crankcase ventilation system. Refer to Crankcase Ventilation System Inspection/Diagnosis.
Split, kinked, or improperly connected vacuum hoses.
Restricted, damaged, leaking, or modified exhaust system from the catalytic converter forward. Refer to Symptoms - Engine Exhaust.
Malfunctioning fuel injectors. Refer to Fuel Injector Diagnosis.
Fuel contamination. Refer to Alcohol/Contaminants-in-Fuel Diagnosis.
Excessive fuel in the crankcase due to leaking injectors. Change engine oil as necessary.
Malfunctioning ignition system. Refer to Electronic Ignition System Diagnosis.
If a condition is found
Repair as necessary.

If no condition is found
Test the engine for any mechanical conditions such as sticking valves, lifters, etc., which could alter the flow into the combustion chamber. Refer to Symptoms - Engine Mechanical.

Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.

Perform the scan tool Fuel Trim Reset after completing the repair.

newdude · April 22, 2024

I find it odd you are missing on 2 and 5 which are on opposite sides of the engine, yet are setting the P219A which is bank 1.

Bank 1 is the driver's side which is 1, 3, 5 and 7. 7 being the closest to the firewall. Bank 2 is the passenger side which is 2, 4, 6 and 8. 8 being the closest to the firewall.

When you had the intake off, did you take a peak at the back of all the valves? Any heavy carbon? Did you see any coolant around the intake ports?

Any ticking or knocking noises?

Just for giggles, original O2 sensors still?

Edited April 22, 2024 by newdude

asilverblazer · April 22, 2024

Intake manifold gasket?

newdude · April 22, 2024

3 hours ago, asilverblazer said:

Intake manifold gasket?

Hopefully OP replaced those as you have to pull the intake to do the injectors.

asilverblazer · April 23, 2024

17 hours ago, newdude said:

Hopefully OP replaced those as you have to pull the intake to do the injectors.

Thats what makes me think they got messed up some how.

ktuck · April 26, 2024

On 4/22/2024 at 11:52 AM, newdude said:

I find it odd you are missing on 2 and 5 which are on opposite sides of the engine, yet are setting the P219A which is bank 1.

Bank 1 is the driver's side which is 1, 3, 5 and 7. 7 being the closest to the firewall. Bank 2 is the passenger side which is 2, 4, 6 and 8. 8 being the closest to the firewall.

When you had the intake off, did you take a peak at the back of all the valves? Any heavy carbon? Did you see any coolant around the intake ports?

Any ticking or knocking noises?

Just for giggles, original O2 sensors still?

Sorry to just getting back to this, I'm going to be out of town for a week or two, sadly my wife's oldest brother passed away and will be with the family for a bit. Actually, I think it will be good for me to take a break from the Silverado and get away from this for awhile and clear my head a little. Thank you for your thoughts and all the info you provided.

Yes, I most certainly looked at the valves and intake ports quite closely. There was some crustyness on the backsides, but not an alarming buildup by any means. I do detect a slight ticking sound, but you have to have your engine in the engine bay to hear it. From within the cab, it isn't detectable. I have spun the engine over with the valve covers removed and all the rocker arms move as normal. As far as the oxygen sensors, they are all original except bank 2 upstream sensor which was replaced a couple months ago with a dense sensor. I can't remember the code that led to its replacement, but that code has not come back since. The intake gaskets were replaced and each time I exercised great care not to dislodge any during manifold reinstall. One new code has set since this second injector replacement, and that is a P050D, rough idle cold start.

ktuck · April 26, 2024

A couple of typo corrections, that should have read "denso" sensor, not dense. And I meant to say "have your ear in the engine bay".

newdude · April 26, 2024

8 hours ago, ktuck said:

Sorry to just getting back to this, I'm going to be out of town for a week or two, sadly my wife's oldest brother passed away and will be with the family for a bit. Actually, I think it will be good for me to take a break from the Silverado and get away from this for awhile and clear my head a little. Thank you for your thoughts and all the info you provided.

Yes, I most certainly looked at the valves and intake ports quite closely. There was some crustyness on the backsides, but not an alarming buildup by any means. I do detect a slight ticking sound, but you have to have your engine in the engine bay to hear it. From within the cab, it isn't detectable. I have spun the engine over with the valve covers removed and all the rocker arms move as normal. As far as the oxygen sensors, they are all original except bank 2 upstream sensor which was replaced a couple months ago with a dense sensor. I can't remember the code that led to its replacement, but that code has not come back since. The intake gaskets were replaced and each time I exercised great care not to dislodge any during manifold reinstall. One new code has set since this second injector replacement, and that is a P050D, rough idle cold start.

Get rid of that Denso and get the OE sensor from the dealer.

ktuck · April 26, 2024

4 hours ago, newdude said:

Get rid of that Denso and get the OE sensor from the dealer.

I have heard that the denso was a worthy option to the OEM O2 sensor, but maybe not you think? Sometimes the info put out on youtube and other videos isn't completely accurate. For instance, there is a guy with video to test MAF sensors that claims that if the engine doesn't die when you unplug the MAF, it is faulty. I know that not to be accurate at all. It was on a Saturday when I replaced the O2 sensor and a denso at autozone was the best I could get at the time without having to order an OEM. Since the negative trim numbers are so out of range on both banks, and each bank has a cylinder misfiring steadily, do you think it a good idea to just break down and replace both sides O2 sensors, at least the upstreams?

newdude · April 26, 2024

14 minutes ago, ktuck said:

I have heard that the denso was a worthy option to the OEM O2 sensor, but maybe not you think? Sometimes the info put out on youtube and other videos isn't completely accurate. For instance, there is a guy with video to test MAF sensors that claims that if the engine doesn't die when you unplug the MAF, it is faulty. I know that not to be accurate at all. It was on a Saturday when I replaced the O2 sensor and a denso at autozone was the best I could get at the time without having to order an OEM. Since the negative trim numbers are so out of range on both banks, and each bank has a cylinder misfiring steadily, do you think it a good idea to just break down and replace both sides O2 sensors, at least the upstreams?

GM ECMs do NOT like any aftermarket sensors. OEM only. I'd start with the one you replaced first and see if anything changes.

ktuck · April 27, 2024

8 hours ago, newdude said:

GM ECMs do NOT like any aftermarket sensors. OEM only. I'd start with the one you replaced first and see if anything changes.

I'll try that even though O2 sensor scan data reflects fairly steady alternating of lean and rich readings. That was the upstream sensor on bank 2. If it was to make a major improvement in fuel trims on that bank, good chance I'll need to do the same for bank 1 upstream sensor as well since the LTFT is nearly negative 20 on that side. I won't be back home until the 4th of May, so it will be a few days before I can do that. I'm way overdue some good news on this truck, I'll let you all know what, if anything changes.

mikeyk101 · April 27, 2024

I am shocked, shocked I tell you that I haven't seen @GMCustomerService step up to try and help out on this issue. This kind of thing is right up their alley and could be easily handled if only they would step up and lend some assistance....

ktuck · April 27, 2024

12 hours ago, mikeyk101 said:

I am shocked, shocked I tell you that I haven't seen @GMCustomerService step up to try and help out on this issue. This kind of thing is right up their alley and could be easily handled if only they would step up and lend some assistance....

I agree. I'm now about 2 months into this diagnosis and continue to come up empty. And its not just me, I've had to an independent speciality shop and to a GM technician. So far, it has defied all logical conclusions and I don't even want to think about the money I've thrown at this.