Subaru Impreza P1582 Engine Trouble Code
What is Subaru Impreza P1582?
Subaru Impreza P1582 code can indicate a faulty oxygen sensor, which may eventually damage the catalytic converter (repair cost: $2,000–$2,200). Professional diagnosis costs around $200–$210. Oxygen sensors are often straightforward to replace — check your owner's manual for location and instructions. This issue should be addressed promptly to prevent further damage.
P1582 on the Subaru Impreza
The Subaru Impreza has a known weak point in the lambda sensor wiring loom where it passes through the floor pan grommet. Road salt and vibration cause the insulation to crack at this point, creating an intermittent open circuit that stores P1582 without a consistent symptom.
Code Information
| Code Type: | OBD-II Powertrain (P) Trouble Code |
| System: | Powertrain |
| Vehicle: | Subaru Impreza |
| Brand: | Subaru |
| Model: | Impreza |
| Code: | P1582 |
P1582 Subaru Impreza Symptoms
Check Engine Light
Illuminated Subaru Impreza dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Subaru Impreza
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Subaru Impreza
Increased Emissions
Failed emissions test due to P1582
P1582 Code Structure
Understanding what each digit means in the P1582 powertrain trouble code:
| P | 1 | 5 | 8 | 2 |
|---|---|---|---|---|
| Powertrain Code | Fuel And Air Metering | Fuel Composition Sensor Circuit Malfunction | Ignition/Distributor Engine Speed Input Circuit Malfunction | Glow Plug/Heater Circuit 'A' Malfunction |
How to Fix Subaru Impreza P1582
Diagnostic Steps:
Regarding P1582, carefully inspect the wire harness near the intake manifold bracket, best accessed from below near the oil filter. Look for chafing, pinching, or damaged insulation.
Repair Solution:
Brake switch circuit concerns may involve open or shorted BPP circuits, damaged switches, or misadjustment. Verify stoplight function and follow proper self-test procedures per service manual.
Technical Notes:
P1582 DTC indicating a sensor fault does not always mean the sensor itself is bad. The issue may stem from the systems being monitored or even the sensor wiring. Proper diagnosis is essential.
Subaru Impreza P1582 Repair Cost
Crankshaft reluctor ring inspection and replacement on the Subaru Impreza is a major service item costing $600–$1,100. Given the labour required to access the component, it is advisable to replace the rear crankshaft seal and crankshaft position sensor simultaneously while the area is open.
P1582 Description
P1582 engine trouble code is related to Glow Plug/Heater Circuit 'A' Malfunction.
Main Cause
The primary reason for P1582 OBD-II Engine Trouble Code is: Fuel Composition Sensor Circuit Malfunction.
Common P1582 Misdiagnosis on the Subaru Impreza
On the Subaru Impreza, the VANOS (variable camshaft timing) solenoid is routinely replaced for P1582 when the actual issue is oil pressure insufficiency. No solenoid will operate correctly if the oil pressure required to actuate the VVT phaser is not present.
DIY Repair Guide: P1582 on Subaru Impreza
Battery terminal cleaning on the Subaru Impreza is a 5-minute job that resolves a surprising number of P1582 intermittents. Use a wire brush and a bicarbonate of soda solution to clean corrosion, then apply a thin coat of petroleum jelly to the terminals after refitting.
Preventing P1582 on the Subaru Impreza
The Subaru Impreza benefits from an intake manifold decarbonisation at 50,000-mile intervals when direct injection is fitted. Carbon build-up on intake valve stems restricts airflow and creates the lean conditions that trigger P1582.
Frequently Asked Questions — Subaru Impreza P1582
A: Simple fixes like a purge valve or gas cap replacement take under an hour. Sensor replacements typically require 1–2 hours of shop time. More involved repairs like VVT actuators or catalytic converters may require a full day or more.