P2342 code meaning
Cylinder 7 Above Knock/Combustion Vibration Sensor Threshold
Powertrain system Generic code P23xx codes Check engine light
What P2342 means
P2342 applies only to engines with seven or more cylinders, in practice V8s and larger. It says the vibration picked up by the knock sensor during cylinder 7's combustion window has exceeded the threshold. On a V8 each bank usually has its own sensor, so the module has to combine sensor choice and crank angle to blame the right cylinder; noise from a loose bracket or the valve train in that window can mimic knock. Saab's GM-based tables therefore run a separate abnormal-noise check between 2,000 and 8,500 rpm to spot a sensor that is not properly bolted. No manufacturer was found that publishes P2342; GM and Saab report single-cylinder knock as P0324. If knock is real, cylinder 7 needs a look at deposits, plug, injector and compression before damage occurs.
P2342 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 8 hours
- Clears after repairAfter a drive cycle
Symptoms of P2342
- Check engine light on
- Possibly audible knocking under load
- Less power from retarded ignition
Common causes of P2342
- PossibleLoose bracket, heat shield or valve train noise in cylinder 7's window
- PossibleDeposits or hot spots in cylinder 7
- Less likelyKnock sensor of that bank loose or wrongly torqued
- Less likelyLow-octane fuel (usually affects several cylinders)
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Knock sensorCylinder 7
What each part of P2342 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 3 | Area: ignition system or misfire. |
| 42 | The exact fault in that area. |
What to do next
- Note P2342 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2342
What does P2342 mean?
P2342 means "Cylinder 7 Above Knock/Combustion Vibration Sensor Threshold". P2342 applies only to engines with seven or more cylinders, in practice V8s and larger. It is a generic code, so it means the same on every make.
Is it safe to drive with P2342?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2342 fail an emissions test?
Yes, it can. P2342 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2342 to fix?
Difficulty: medium. A typical repair takes 0.5 to 8 hours of work. This is a job for a workshop.
Will P2342 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.