Is P0202 the same fault as P0201?

No. P0201 is an open circuit on cylinder 1, P0202 on cylinder 2. The fault type is identical but it affects a different injector, so it is the same procedure carried out on the cylinder 2 circuit.

Can a blocked injector cause P0202?

Not on its own. P0202 is purely electrical - an open circuit. A blocked but electrically sound injector would more likely set a lean or misfire code rather than an open-circuit fault.

Why does only cylinder 2 misfire?

Each injector has its own circuit. An open circuit on cylinder 2 stops just that injector firing, so the misfire is isolated to that cylinder while the others keep running.

How much will it cost to fix?

A petrol injector is often £30–£80 plus fitting. Diesel common-rail injectors are dearer at £150–£500 and usually need coding. A wiring repair can cost very little if you trace it yourself.

Do diesel injectors need coding after replacement?

Yes. Common-rail diesel injectors carry a calibration code that must be written to the ECU so it meters fuel correctly. Most petrol injectors need no coding.

Can I drive with P0202?

Only the short distance needed to reach help. A dead cylinder risks catalytic converter damage and leaves the car gutless, so it is not a fault to live with.

P0202 - Injector Circuit Open - Cylinder 2

What Is P0202?

P0202 is logged when the engine ECU sees an open circuit on the cylinder 2 injector. In plain terms the electrical loop that should carry the firing pulse to that injector is broken, so the injector never opens and cylinder 2 gets no fuel at all.

Because the cylinder is effectively dead, the engine runs on the cylinders that remain and shakes noticeably. Raw air is pumped through cylinder 2 into the exhaust, upsetting the lambda readings and, on petrol engines, quickly overheating the catalytic converter. It needs sorting promptly.

Common Symptoms

Heavy misfire, most obvious at idle
Flashing engine management light under load
Clear lack of power and hesitation
Strong fuel or sulphur smell from the exhaust
Higher fuel use as the ECU richens the other cylinders
Vibration through the gear lever and pedals

Common Causes

Open injector winding - the solenoid coil inside the cylinder 2 injector has gone open circuit, the single most common cause.

Damaged connector - a cracked or unclipped plug on the cylinder 2 injector letting the pins lose contact.

Chafed or broken wire - the short feed from the loom rubbed through, often near a bracket or the rocker cover.

Corroded terminals - green corrosion in the connector raising resistance until the circuit reads open.

Fuse or relay - a blown injector supply fuse can knock out a bank of injectors, so check power first.

ECU driver fault - a failed injector driver inside the ECU, uncommon but worth considering at high mileage.

How to Diagnose P0202

Confirm Which Cylinder

Cylinder 2 is the second injector from the timing-belt end of the engine. Identify it positively before testing so you are not chasing the wrong injector.

Listen With a Stethoscope

With the engine idling, place a stethoscope on each injector. A healthy injector ticks steadily; silence on cylinder 2 confirms no pulse is getting through.

Measure Injector Resistance

Unplug the cylinder 2 injector and measure across its terminals. Petrol units usually read 12–16 ohms, diesels around 0.5–2 ohms. An infinite reading proves the winding is open.

Back-Probe the Connector

Reconnect and back-probe the connector while cranking. You should see supply voltage and a switching earth. A missing earth points upstream to wiring or the ECU driver.

Continuity Back to the ECU

Unplug both ends and check continuity along each wire from the injector plug to the ECU connector. A break here is your open circuit; inspect where the loom passes hot or sharp edges.

Swap to Prove It

Still unsure? Swap the cylinder 2 injector with one from another cylinder. If the dead cylinder moves with the injector, the injector is at fault, not the wiring.

Protect the CatalystA completely dead cylinder dumps unburnt fuel and oxygen into the exhaust. On petrol engines this can melt the catalytic converter within minutes at motorway speeds, so keep journeys short until P0202 is fixed.

Verdict

Start with a resistance test on the cylinder 2 injector - an open winding is the usual answer. If the injector reads normally, the fault is in the connector or wiring, so back-probe and check continuity to the ECU before condemning anything.

Want the full picture? The OBD Fault Code Plain English Guide (PDF) covers the most common UK fault codes in one plain-English download.