CarScan
P0305Powertrain

Cylinder 5 misfire detected

Where to start

Misfire in cylinder five. The same move as P0301: swap the coil and the plug with a neighbouring cylinder and see whether the code follows. If the lamp is BLINKING, do not keep driving — the catalyst is burning.

What the cylinder number gives you

The last digit names the cylinder: 5. That is the most useful thing in this code — it turns a search across the whole engine into a check of one cylinder.

Swap and watch. Move the plug and the coil between cylinder 5 and a neighbour, clear the code and drive. If the fault follows the part, the part is to blame. If it stays on cylinder 5, the cylinder is: the injector, compression, a valve. This is the only way to tell one from the other without taking anything apart.

⚠️ Misfire is not only ignition. Check fuel trims: a large plus on one bank points to air, not to the plug. And do not clear the code before the swap — you lose the evidence.

A code is not a diagnosis. It says which check failed, not which part to replace. Clearing it without repair only means the car will report it again in a few trips.

How to put together a report a mechanic will actually read

How the code is built

Letter — the systemPowertrain: engine and transmission
Common or the maker's ownGeneric code: the same on every car
Which part of the engineIgnition system and misfires
Number of the faultThe serial number inside that group — it does not say how serious the fault is

All codes in «Ignition system and misfires»

How the app helps

CarScan reads this code from your car through an OBD-II adapter, shows whether it is active now or only stored, names the module that reported it, and puts it into a plain-text report for your mechanic.

See what the app does

Unfamiliar word? Open the glossary

What the letter and the four digits mean