P0301 on 2010-2017 Chevrolet Suburban: Cylinder 1 Misfire Causes and Fixes

What's Unique About the 2010-2017 Chevrolet SUBURBAN

The 2010-2017 Suburban V8 engines feature Active Fuel Management (AFM), which deactivates certain cylinders (including cylinder 1) under light loads to improve fuel economy. This system's specialized lifters are a known, widespread failure point and a primary cause of misfire codes like P0301 that go beyond typical ignition or fuel issues. When these lifters fail, they can get stuck, collapse, or even spin in their bores, leading to a loss of valve function and a persistent misfire. The 2015-2017 models with direct injection (EcoTec3 engines) can also be prone to heavy carbon buildup on intake valves, which can restrict airflow and cause misfires.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Generation note: This range covers two Suburban generations. The 2010-2014 models belong to the 10th generation (GMT900 platform). The 2015-2017 models are the 11th generation (K2XX platform), which introduced direct injection (EcoTec3 engines). This makes the later generation more susceptible to carbon buildup on intake valves as a cause for misfires. Both generations use Active Fuel Management (AFM) and are prone to lifter failures, which is one of the most-discussed issues on owner forums for these trucks.

Symptoms You May Notice

• Rough or shaky idle
• Engine hesitation or stumbling during acceleration
• Noticeable loss of power
• Flashing or solid Check Engine Light
• Smell of unburned gasoline from the exhaust
• Reduced fuel economy
• Engine ticking or tapping noise that increases with RPM
• "Service StabiliTrak" message appearing with the Check Engine Light

Most Likely Causes

1. Worn Spark Plug 🔴 High Probability Spark plugs are a standard wear item. Owners and mechanics in forums strongly recommend using OEM ACDelco Iridium plugs. Using other brands has been anecdotally linked to persistent, hard-to-diagnose misfires. The recommended plug was updated from 41-110 to 41-162 for Gen IV engines (pre-2014).
   How to confirm: Remove the spark plug from cylinder 1 (front driver's side) and inspect it for wear, fouling (black, sooty, or oil-wet deposit), or damage to the electrode or porcelain. An oil-fouled plug can indicate a more serious issue like a bad valve cover gasket or piston ring issue.
   Typical fix: Replace the spark plug. It is highly recommended to replace all 8 plugs at the same time with high-quality OEM-spec ACDelco Iridium plugs (41-162 for 2010-2014, 41-114 for 2015-2017) and new wires.
   Est. part cost: $8-$20 per plug
2. Faulty Ignition Coil 🔴 High Probability
   How to confirm: Swap the ignition coil from cylinder 1 with another cylinder (e.g., cylinder 3, the next one back on the same side). Clear the codes and drive the vehicle. If the code changes to P0303, the coil is bad.
   Typical fix: Replace the faulty ignition coil. ACDelco is the OEM brand. The square D510C (or D521C) coil is a common part number for these engines.
   Est. part cost: $40-$80
3. Bad Spark Plug Wire 🟡 Medium Probability A GM Technical Service Bulletin (PIP4819A) specifically calls out inspecting and replacing loose spark plug wires for misfire codes on these vehicles. Wires can also degrade over time, causing weak spark.
   How to confirm: Visually inspect the wire for damage, corrosion, or a loose connection at the coil or spark plug. You can test its resistance with a multimeter. A simple test is to start the engine in the dark and look for any arcing along the wire.
   Typical fix: Replace the spark plug wire. It's often best to replace the full set with a quality brand like ACDelco or NGK.
   Est. part cost: $50-$100 for a set
4. Failed AFM/DFM Lifter 🟡 Medium Probability The Active Fuel Management (AFM) system uses special hydraulic lifters on cylinders 1, 4, 6, and 7 that are known to fail, getting stuck, collapsing, or damaging the camshaft. This is a very common and well-documented issue on 5.3L and 6.2L GM engines, frequently discussed in owner forums.
   How to confirm: This is a more advanced diagnosis. It often starts with a characteristic ticking or tapping noise from the engine. A compression test on cylinder 1 will likely show low readings. The definitive check is to remove the driver's side valve cover and check for play in the rocker arms for cylinder 1; excessive movement indicates a collapsed lifter.
   Typical fix: This is a major repair that involves removing the cylinder head to replace the faulty lifters. Many owners and shops opt to replace all lifters (both AFM and standard), the lifter guides, and inspect or replace the camshaft at the same time. Some install an AFM-delete kit to prevent future failures, which requires a corresponding ECU tune.
   Est. part cost: $400-$1000 for lifters, gaskets, and bolts. A full AFM delete kit with a new camshaft can be $800-$1500.
5. Clogged or Faulty Fuel Injector ⚪ Low Probability
   How to confirm: Listen for a clicking sound from the injector with a mechanic's stethoscope. You can also swap the injector with another cylinder, similar to the coil swap test, though this is more labor-intensive.
   Typical fix: Replace the faulty fuel injector. It's recommended to replace the seals on adjacent injectors if the fuel rail is removed.
   Est. part cost: $50-$120

Rare But Worth Checking

• Intake Manifold Gasket Leak: The plastic intake manifolds on these V8s can develop vacuum leaks at the cylinder head mating surface, causing a lean condition and misfire on the affected cylinder. This would typically be accompanied by a lean code (P0171/P0174).
• Carbon Buildup on Intake Valves: Primarily affects the 2015-2017 direct-injected (EcoTec3) engines. Since fuel is sprayed directly into the cylinder, it no longer cleans the back of the intake valves, allowing carbon to build up and restrict airflow, causing misfires. Cleaning requires removal of the intake manifold and media blasting (e.g., walnut shells).
• Low Engine Compression: Caused by more serious mechanical issues like worn piston rings, a damaged valve, or a leaking head gasket. A compression test and cylinder leak-down test will confirm this.
• Failed Valve Lifter Oil Manifold (VLOM): This component, located under the intake manifold, directs oil pressure to the AFM lifters. A failure in the solenoid or gasket for cylinder 1 can cause the lifter to malfunction. It is often replaced during an AFM lifter job.

Diagnosis Steps

1. Read the code with an OBD-II scanner and check for any other pending or stored codes. Note the freeze frame data.
2. Listen for an engine tick. A distinct ticking or tapping noise that gets faster with RPM is a strong indicator of a potential AFM lifter failure.
3. Perform an ignition coil swap. Swap the ignition coil from cylinder 1 to cylinder 3. Clear codes and run the engine. If the code changes to P0303, the coil is the culprit.
4. Inspect the spark plug and wire. If the code remains P0301, remove the spark plug and wire from cylinder 1. Inspect for wear, damage, or deposits (oil or carbon). An oil-fouled plug is a significant clue.
5. Replace ignition components. If the plug or wire looks suspect, replace it. It's best practice to replace all 8 plugs and wires. Ensure you use high-quality ACDelco parts as specified for the engine.
6. Check the fuel injector. If ignition components are confirmed good, listen to the injector with a stethoscope for a steady clicking. A 'noid' light can confirm if it's receiving an electrical pulse.
7. Perform a compression test. If the misfire persists, a compression test is necessary. A significantly lower reading on cylinder 1 compared to others points to a mechanical problem.
8. Inspect valvetrain. If compression is low, the next step is to remove the driver's side valve cover to inspect the rocker arms and valve springs for cylinder 1. Excessive play in the rocker arms confirms a collapsed lifter.

Parts You'll Likely Need

• Spark Plug (OEM #ACDelco 41-162 (2010-2014), ACDelco 41-114 (2015-2017))
• Ignition Coil (OEM #ACDelco D510C / D521C)
• Spark Plug Wire Set
• AFM Lifter Kit (with gaskets) (OEM #12645725, 12571595)
• Fuel Injector (OEM #12613411)

Related Codes That Often Appear With This One

• P0300 — If the misfire is intermittent or starting to affect other cylinders, a P0300 (Random/Multiple Cylinder Misfire) may be stored alongside P0301. This is common during an AFM lifter failure.
• P030x — If other specific cylinder misfire codes are present (e.g., P0307, P0304, P0306), it strongly points towards a systemic issue like a failing AFM system, as those are the other AFM cylinders.
• P050D — Cold Start Rough Idle may be present, sometimes related to carbon buildup or other fuel/air metering issues that can also contribute to misfires.

Technical Service Bulletins (TSBs) & Recalls

• PIP4819A: Mentions inspecting and replacing loose spark plug wires for misfire codes.
• 19-NA-219: Discusses engine misfire (P0300, P0301, etc.) caused by a worn camshaft lobe or a collapsed AFM lifter.

Platform-Specific Known Issues

• AFM Lifter Failure Diagnosis Path: A common story on forums for the 2010-2017 Suburban starts with a P0301 code. The owner first replaces the spark plug, spark plug wire, and ignition coil for cylinder 1. When the misfire persists, further diagnosis reveals a ticking noise and low compression, ultimately leading to the discovery of a collapsed AFM lifter. This pattern is documented repeatedly.
• The Importance of OEM Spark Plugs: Multiple owners have reported chasing a P0301 misfire after a tune-up, only to find the issue was caused by using non-ACDelco spark plugs. Switching back to the recommended ACDelco Iridium plugs resolved the misfire where aftermarket plugs did not.
• AFM Failure Repair and Prevention: When faced with a confirmed AFM lifter failure, many owners opt for a full 'AFM delete'. This involves replacing the special AFM lifters with standard lifters, replacing the camshaft, and reprogramming the ECU to permanently disable the cylinder deactivation feature. While expensive, it's seen as a permanent solution to a common design flaw.

Mechanic-Grade Diagnostic Values

• Ignition Coil Primary Winding Resistance — expected: 0.4 to 2.0 ohms. Failure: A reading outside this range indicates a faulty coil.
• Ignition Coil Secondary Winding Resistance — expected: 6,000 to 10,000 ohms. Failure: A reading outside this range suggests the coil cannot produce a strong enough spark.
• Fuel Pressure (2010-2014 Port Injection) — expected: 55-62 PSI with key-on, engine-off. Failure: Pressure below this range can cause lean misfires, though it would typically affect multiple cylinders.
• Fuel Pressure (2015-2017 Direct Injection, Low Pressure Side) — expected: 50-75 PSI at idle. Failure: Low pressure from the in-tank pump can starve the high-pressure pump.
• Fuel Pressure (2015-2017 Direct Injection, High Pressure Side) — expected: ~500-600 PSI at idle. Failure: Pressure that is erratic or does not match the commanded pressure can indicate a failing High Pressure Fuel Pump (HPFP).
• Cylinder Power Balance RPM Drop — expected: A relatively even RPM drop across all cylinders when each is individually disabled.. Failure: Little to no RPM drop on cylinder 1 indicates it is not contributing power, confirming the misfire.

Hidden / Shadow Codes Worth Checking

• Mode $06, Test ID $A2 (Cylinder 1 Misfire Data): This is not a separate trouble code, but a specific monitor within the OBD-II system that tracks the raw misfire count for cylinder 1. It can show misfires occurring even if they haven't reached the threshold to set the P0301 code and light the check engine light. (see via A professional scan tool or an advanced OBD-II app that can access Mode $06 test results.)

Scan Tool Commands That Help

• GDS2 / Tech2 / Professional Scan Tool: Cylinder Power Balance Test — This is a crucial diagnostic step to confirm if cylinder 1 is truly the non-contributing cylinder. The scan tool disables the fuel injector for each cylinder one by one and measures the RPM drop. If disabling cylinder 1 causes little or no drop compared to others, it confirms a lack of combustion.
• GDS2 / Tech2 / Professional Scan Tool: AFM Cylinder Deactivation (Special Functions) — To test the functionality of the Active Fuel Management system. A technician can command the AFM solenoids on and off to see if the system is responding. This can help isolate a problem between the VLOM, the solenoid for cylinder 1, and the lifter itself.
• GDS2 / Tech2 / Professional Scan Tool: Fuel Injector Balance Test — This test measures the pressure drop in the fuel rail as each injector is fired for a set duration. A smaller pressure drop for cylinder 1 compared to others would indicate a clogged or restricted injector.

Wiring & Ground Locations

• G102 — Located at the left rear of the engine.. This is the primary ground for all 8 ignition coils. A loose or corroded connection here can cause weak or intermittent spark on multiple cylinders, potentially being misdiagnosed as individual coil failures.
• G103 — Located on the cowl at the left rear of the engine compartment, above the brake booster.. This ground serves the Engine Control Module (ECM) and Body Control Module (BCM). A poor connection can cause a wide range of erratic engine management behavior, including incorrect sensor readings and misfire detection.
• Engine Harness (Driver's Side) — The main engine harness running along the driver's side fuel rail and valve cover.. This section of the harness contains the wiring for the cylinder 1 ignition coil and fuel injector. It is susceptible to heat damage and chafing against engine components, which can lead to shorts or open circuits for those specific components.

Real Owner Repair Stories

• YouTube channel '15th Street Automotive' (2004 GMC Sierra 5.3L (similar Gen IV engine architecture)) — Severe misfire, tapping noise from under the hood, check engine light.
  ❌ Tried (didn't work) Initially suspected a common AFM lifter failure due to the tapping noise.
  ✅ What actually fixed it Upon removing the valve cover, a broken valve spring was discovered on the misfiring cylinder. The broken spring prevented the valve from closing properly, causing a complete loss of compression and a loud mechanical tap.

OEM Part Supersession History

• ACDelco 41-110 → ACDelco 41-162 — The 41-162 has a slightly longer threaded portion, intended to place the electrode more centrally in the combustion chamber for improved efficiency on Gen IV engines (pre-2015).
  Heads up: While 41-162 is the recommended replacement for 41-110, some users have reported preferring the performance and build quality of the older 41-110 plugs. The 41-114 plug for 2015+ EcoTec3 engines is physically different and not interchangeable.
• Various AFM Lifter PNs (e.g., 12571595, 12619820, 12639516) → Newer DFM-style lifters (e.g., GM 12680871, Elgin HL-7025) — GM introduced a revised lifter design for the newer Dynamic Fuel Management (DFM) engines. This new lifter is backwards compatible with the older AFM systems and is considered a more robust design.
  Heads up: The new DFM lifter (HL-7025) can be used in older AFM engines, but the original AFM-only lifter (HL-7011) cannot be used in newer DFM engines.

Model Year Variations Within This Range

• 2010-2014 (GMT900): These models use Gen IV Vortec engines with port fuel injection. Fuel pressure is regulated by an in-tank pump and a Fuel Pump Control Module (FPCM). Misfire diagnosis is primarily focused on ignition, AFM lifters, and standard fuel injectors.
• 2015-2017 (K2XX): These models use Gen V EcoTec3 engines with Direct Injection (DI). This adds a High Pressure Fuel Pump (HPFP) and makes the intake valves susceptible to carbon buildup, which can cause misfires. Fuel system diagnosis is more complex, involving both a low-pressure and high-pressure side.