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What P0302 means for your Chevy Silverado
Your Silverado's ECM detected that cylinder 2 isn't firing properly - the crankshaft position sensor saw the rotational speed dip slightly each time cylinder 2 was supposed to combust. On the 5.3L V8 Silverado, P0302 is most often AFM (Active Fuel Management) lifter collapse on cyl-1 or cyl-7 (firing-order paired), though stuck lifters and worn AFM solenoids can also cause cyl-2 misfires after 80k miles.
🎯 Top Causes on the Chevy Silverado
50%
#1 CAUSE
AFM/DOD Collapsed Lifter (5.3L)
2007-2014 Silverado 5.3L (LMG, L83) engines use Active Fuel Management - the engine deactivates 4 of the 8 cylinders by collapsing their lifters during light cruise. The lifters on the AFM cylinders (1, 7, 4, 6 in the firing order) can permanently collapse, but failure of the lifter retention mechanism can also lock a non-AFM lifter and cause a steady cyl-2 misfire with a tick noise. Range Technology AFM-disable device is a popular preventive measure; permanent fix is lifter replacement and an AFM delete tune.
Lifter Set
$180-$400
AFM Delete Kit
$500-$900
Lifter Replace (Shop)
$1800-$3500
30%
#2 CAUSE
Cylinder 2 Ignition Coil or Plug
The 5.3L and 6.2L use individual coils mounted on the valve covers. The cyl-2 coil sits on the driver-side rear and is exposed to underhood heat. ACDelco D513A is the OEM coil (about $60); NGK U5023 is a reliable replacement. Always check plugs at the same time - AC Delco 41-985 iridium, gapped 0.040". A worn plug ruins a new coil in months.
OEM Coil
$60-$110
Aftermarket
$40-$70
w/Labor
$120-$240
20%
#3 CAUSE
Stuck AFM Solenoid or Oil-Pressure Issue
AFM uses oil-pressure-activated valve lifters. A clogged AFM solenoid (in the valley pan under the intake manifold) or sludged oil supply causes a lifter to hang in the wrong mode and misfire. Symptom: misfire goes away on heavy throttle but returns at cruise. Replacing the AFM solenoid is a 3-4 hour job (intake comes off). Use Mobil 1 5W-30 or thicker and change every 5000 miles to prevent recurrence.
AFM Solenoid
$80-$140
Valley Cover Gasket
$25-$50
w/Labor
$400-$700
🚗 Most Affected Silverado Model Years
| Year | Engine | Primary Cause | Typical Mileage | Notes |
|---|---|---|---|---|
| 2007-2014 | 5.3L LMG (Gen IV AFM) | AFM lifter / coil | 80k-140k | Highest P0302 / lifter reports |
| 2014-2019 | 5.3L L83 (Gen V DI AFM) | AFM lifter, DI carbon | 60k-120k | Worst lifter generation per TSB |
| 2019-2020 | 5.3L L84 (DFM) | Lifter / coil | 40k-90k | Dynamic Fuel Mgmt - early failures reported |
| 2014-2020 | 6.2L L86/L87 | Lifter or coil | 80k-140k | Less common but possible |
🔧 How to Diagnose P0302 on a Chevy Silverado
- Listen for a tick. A failed AFM lifter sounds like a sewing machine on top of the engine. With the hood up and engine idling, use a long screwdriver as a stethoscope on each valve cover. The bad lifter side will tick noticeably.
- Pull the cyl-2 coil and swap it with cyl-4. Clear code, drive 5 minutes. If misfire follows the coil, replace it. If it stays on cyl 2, suspect lifter.
- Check fuel trims and AFM status with a scanner that supports GM modes (BlueDriver, OBDLink MX+, or Tech 2). AFM should activate above 1000 rpm in light cruise. If AFM is stuck active or inactive on one bank, suspect the solenoid.
Want a step-by-step walkthrough specific to your Chevy Silverado? Run a $5.99 AI diagnosis report - we narrow the cause to your year, engine, and symptoms.
❓ Frequently Asked Questions
Is the AFM lifter problem covered under warranty?
There is no GM-wide warranty extension as of this writing, but a 2024 class-action settlement (Siqueiros v. GM) covers many 2014-2018 5.3L L83 and 6.2L L86 trucks for lifter and AFM-related repairs. Check your VIN at the official settlement site. Most claims pay $5,500-$8,000 in repair reimbursement.
Should I install an AFM disabler?
If your 5.3L L83 or 6.2L L86 has under 80k miles, yes - a Range Technology AFM disabler ($170) keeps all 8 cylinders firing and prevents lifter collapse. It does not eliminate existing damage and slightly hurts fuel economy (~1 MPG). For permanent peace of mind, an AFM-delete tune and hardware swap costs $1500-$2000.
How do I know if my Silverado P0302 is a coil or a lifter?
Coil: misfire is steady at all RPM, no ticking noise. Lifter: misfire often goes away under throttle, comes back at cruise, with a sewing-machine tick from the top of the engine.
How much does it cost to replace a collapsed lifter on a 5.3L?
DIY: $200-$500 in parts (full lifter set, gasket kit, RTV) and 8-12 hours. Shop: $1800-$3500 depending on whether the cam shows damage. If the cam is gouged, add $400-$700 for a new cam. AFM delete is a worthwhile add-on if you're already in there.
Which cylinder is cylinder 2 on a Silverado V8?
GM small-block V8s number 1-3-5-7 on the driver side and 2-4-6-8 on the passenger side. Cyl 2 is the front-most cylinder on the passenger side.
See all P0302 causes (all vehicles) → · Related: Chevy 5.3L AFM Lifter Failure →