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DTC/P0305·Jeep

P0305 on Jeep: Causes, Symptoms and Fix Cost

Quick Answer
High SeverityNot safe to driveJeep

P0305 on a Jeep means the ECU counted enough missed combustion events on cylinder 5 to trip the misfire monitor. Expect rough running and a flashing check engine light under load.

Typical repair cost, all makes€45 - €2700

Connect any standard Bluetooth OBD2 adapter to your Jeep and Skanyx tells you what P0305 means on that engine, whether it is safe to keep driving, and what the fix should cost. Free on iPhone and Android.

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What does P0305 mean on a Jeep?

The Quick Answer above is the generic definition. What follows is the model-specific detail for the Jeep models that log P0305.

Jeep Grand Cherokee 5.7L HEMI

2005-2018

The HEMI runs 16 plugs (two per cylinder). MDS cylinder deactivation applies to cylinders 1, 4, 6 and 7, so on cylinder 5 a persistent misfire is almost always coil, plug, or a collapsed lifter rather than an MDS fault.

What causes P0305 on a Jeep?

Beyond the generic causes listed on the main P0305 page, these are the patterns noted for Jeep models:

Jeep Grand Cherokee 5.7L HEMIOne of the two plugs on cylinder 5 fouled while the other reads fine
Jeep Grand Cherokee 5.7L HEMICollapsed roller lifter wiping the cam lobe (common HEMI failure)
Jeep Grand Cherokee 5.7L HEMIExhaust manifold bolt breakage causing a localised leak that trips the misfire monitor

How to diagnose P0305 on a Jeep with OBD2

Follow these steps to pinpoint the root cause of P0305:

  1. Read all stored and pending codes. Note fuel trims and any lean/rich codes (P0171, P0174) that could point at a vacuum or injector issue.
  2. Pull the coil and plug from cylinder 5. Fouled electrode, cracked insulator, or oil in the plug well tells you a lot before you swap anything.
  3. Swap the cylinder 5 coil with a neighbouring cylinder, clear codes, and drive. If the code moves (e.g. becomes P0303), replace the coil.
  4. Swap the injector connector or the injector itself with a neighbour if the coil swap didn't move the misfire. A noid light confirms the ECU is pulsing the injector.
  5. Check live fuel trims and misfire counters with a scan tool. Positive trim on the affected bank points to vacuum leak or weak injector flow.
  6. Smoke-test the intake if trims are lean. Cracked PCV hoses and split intake boots are common culprits.
  7. Compression test cylinder 5. More than 15% below the average of the other cylinders points to mechanical trouble. Follow up with a leakdown to isolate valves vs rings.
  8. After repair, clear codes and complete a misfire monitor drive cycle before declaring victory.

How much does P0305 cost to fix on a Jeep? (EUR)

Estimated repair costs for P0305 in EUR, compiled across makes. Expect Jeep parts and labour towards the upper end of each range.

Repair Parts Cost Labor Cost Total Estimate DIY Difficulty
Replace spark plug on cylinder 5 (usually do the full set) €15–€80 €30–€120 €45–€200 Easy
Replace ignition coil on cylinder 5 €40–€180 €30–€90 €70–€270 Easy
Replace or ultrasonically clean fuel injector on cylinder 5 €80–€350 €100–€300 €180–€650 Moderate
Intake manifold gasket replacement to fix a vacuum leak €40–€150 €150–€400 €190–€550 Moderate
Cylinder head work after failed compression/leakdown (valve job or head R&R) €300–€1200 €400–€1500 €700–€2700 Professional

Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.

These codes are often seen alongside P0305 or point to related issues, on any make:

P0300P0301P0304P0306P0316

Looking for the full P0305 reference (all makes, full diagnosis flow, complete repair cost matrix)?

See the main P0305 guide
Skanyx · Jeep

Diagnose P0305 on your Jeep

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