OBD-II code · Powertrain (generic)
P0099 Intake Air Temperature Sensor 2 Circuit Intermittent/Erratic Bank 1
Intermittent dropouts or noise on IAT sensor 2 bank 1 signal. The intake air temperature sensor feeds the ECM's density calculation — a drifted reading miscalculates fuel mass and pushes mixture lean (cold reading) or rich (hot reading).
Is it safe to drive with P0099?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyConnector loose or corroded
- Less likelyConnector with intermittent contact under vibration
- Less likelyHarness routed against vibrating component
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–1 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Iat Sensor 2, Sensor Wiring
Related codes
- P00A9Intake Air Temperature Sensor 2 Circuit Intermittent/Erratic Bank 2
- P00ECIntake Air Temperature Sensor 3 Circuit Intermittent/Erratic Bank 1
- P00F1Intake Air Temperature Sensor 3 Circuit Intermittent/Erratic Bank 2
- P0096Intake Air Temperature Sensor 2 Circuit Range/Performance Bank 1
- P0097Intake Air Temperature Sensor 2 Circuit Low Bank 1
- P0098Intake Air Temperature Sensor 2 Circuit High Bank 1
- P009AIntake Air Temperature/Ambient Air Temperature Correlation
- P009BFuel Pressure Relief Control Circuit/Open
- P009CFuel Pressure Relief Control Circuit Low
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.