P02F1

Cylinder 4 Injector Circuit Range/Performance

Fuel injector circuit Generic OBD-II High

What it means

P02F1 means the ECM sees the cylinder 4 fuel injector's electrical signal drifting outside its expected range. That usually points to a failing injector or a wiring/connection problem on that cylinder, which can make cylinder 4 misfire and run rough until it is repaired.

High

Can I keep driving? You can usually drive, but cylinder 4 may misfire and run rough — fix it promptly to avoid unburned fuel damaging the catalytic converter.

Real-world scan data

Seen in

346

scans in the past year

Found in

0.1%

of scans

0.1%

of scans that found faults

Appears alongside · share of P02F1 scans

P02F0in 81.2% of scans

P02EEin 79.8% of scans

P02EFin 79.2% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Rough running or a misfire from cylinder 4
Hesitation or reduced power under load
Occasional rough idle

Common causes

Most likely first

Failed fuel injector on cylinder 4Likely
Open, shorted, or chafed wiring to the cylinder 4 injectorCommon
Poor or corroded connection at the injector connectorCommon
Injector driver fault in the ECM or injector control module (less common)Less often

How to diagnose & fix

Work through it in order

Read freeze-frame data and confirm the fault is on cylinder 4.
Inspect the injector connector and wiring for damage, corrosion, or a loose pin.
Measure the injector's resistance and compare it to the other injectors.
Check injector control/driver supply and ground circuits at the module.
Replace the cylinder 4 injector if it is out of spec; clear and re-test.

FAQ

Quick answers

Is it safe to drive with P02F1?+

Short trips are usually fine, but a misfiring cylinder dumps raw fuel into the exhaust and can overheat the catalytic converter, so repair it soon.

Can I just clear P02F1?+

It will come back until the injector or its circuit is fixed. Clearing only resets the light temporarily.

Read & clear P02F1 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX