P3498 code meaning
Cylinder 1 Deactivation/Intake Valve Performance
Powertrain system Generic code P34xx codes Check engine light
What P3498 means
P3498 flags a mechanical failure on cylinder 1: the control unit commanded it off, but its valves kept opening. This differs from P3402, which concerns the control side, and from the wiring codes P3401, P3403 and P3404. GM runs the check on its 5.3 l L84 and 6.2 l L87 Dynamic Fuel Management V8s by watching filtered manifold pressure every 90 crank degrees; if it stays above a threshold while cylinder 1 should be resting, 22 failures in 25 chances log a Type B code. Mazda's 2.5 l engines, which deactivate cylinders 1 and 4, show it together with P349B when a rocker arm has dropped out or broken (SA-041/18, SA-022/19); Mazda then authorises a replacement engine. Drivers notice the lamp, rough running or a loss of power.
P3498 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyHard
- Typical labor0.5 to 16 hours
- Clears after repairAfter a drive cycle
Symptoms of P3498
- Check engine lamp on
- Rough idle or misfire on cylinder 1 (P0301)
- Clatter from the cylinder head and loss of power
- Cylinder deactivation no longer used, higher fuel use
Common causes of P3498
- Most likelySwitchable rocker arm of cylinder 1 dropped out or broken (Mazda)
- PossibleDeactivation lifter of cylinder 1 stays locked (GM DFM)
- PossibleLifter oil solenoid of cylinder 1 sticking or with protruding pole piece
- PossibleOverdue oil changes or wrong oil grade
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
LifterValve trainCylinder deactivation solenoidEngine oil
What each part of P3498 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 3 | Mixed range: generic and manufacturer-specific codes. |
| 4 | Area: auxiliary emission controls (catalytic converter, EGR, EVAP). |
| 98 | The exact fault in that area. |
What to do next
- Note P3498 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 P3498
What does P3498 mean?
P3498 means "Cylinder 1 Deactivation/Intake Valve Performance". P3498 flags a mechanical failure on cylinder 1: the control unit commanded it off, but its valves kept opening. It is a generic code, so it means the same on every make.
Is it safe to drive with P3498?
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 P3498 fail an emissions test?
Yes, it can. P3498 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 P3498 to fix?
Difficulty: hard. A typical repair takes 0.5 to 16 hours of work. This is a job for a workshop.
Will P3498 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.