P0278

Cylinder 6 Contribution/Balance

Q: Is it safe to drive with P0278?

For short trips, yes, but cylinder 6 isn't pulling its weight, so the engine runs rough and may misfire. Prolonged misfire can harm the catalytic converter, so address it soon.

Q: Can I just clear P0278?

It returns until the weak cylinder is fixed. Diagnose the injector or mechanical cause instead of clearing it.

Fuel injectors / cylinder balance Generic OBD-II High

What it means

P0278 means the ECM has determined that cylinder 6 isn't contributing its expected share of power compared with the other cylinders. This balance fault usually points to a fueling problem — a worn, clogged, or leaking injector — or a mechanical weakness such as low compression on that cylinder. The engine runs unevenly and may misfire.

High

Can I keep driving? Drivable short-term, but cylinder 6 is underperforming — expect rough running and possible misfire, and get it checked before it worsens.

Real-world scan data

Seen in

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

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 idle or vibration
Misfire or hesitation
Reduced power
Uneven running, possible smoke on a diesel

Common causes

Most likely first

Worn, clogged, or leaking cylinder 6 injectorLikely
Low compression or a mechanical issue on cylinder 6Common
Fuel-delivery problem (pressure or filter) affecting that cylinderCommon
Wiring or connector fault at the injectorLess often
Intake or vacuum leak near cylinder 6Less often

How to diagnose & fix

Work through it in order

Read freeze-frame data and check for a cylinder-6 misfire (P0306) or injector codes.
Compare per-cylinder injector data and fuel trims with a scan tool.
Test, clean, or replace the cylinder 6 injector.
Run a compression test if the fueling checks out.
Repair any wiring faults, then clear the code and re-test.

FAQ

Quick answers

Is it safe to drive with P0278?+

For short trips, yes, but cylinder 6 isn't pulling its weight, so the engine runs rough and may misfire. Prolonged misfire can harm the catalytic converter, so address it soon.

Can I just clear P0278?+

It returns until the weak cylinder is fixed. Diagnose the injector or mechanical cause instead of clearing it.

Read & clear P0278 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