P0152

O2 Sensor Circuit High Voltage (Bank 2 Sensor 1)

Car Fault Codes Emissions & exhaust

Can you still drive? Yes, normally

Who can fix it? DIY with some experience

Typical repair time 30 minutes – 2.5 hours

Typical cost SAR 100 to 1,200

What it means

The engine computer has seen the bank 2 upstream oxygen sensor voltage stay above the allowed limit. The cause may be a short feeding extra voltage into the signal wire, a failed sensor, or a truly rich mixture on that bank, for example from a leaking injector.

Symptoms4

Check engine light on.
Hesitation or weak acceleration if the computer leans bank 2 too much.
Fuel smell from the exhaust if the mixture really is rich.
Change in fuel consumption.

Possible causes6

Signal wire shorted to the heater supply or another voltage source in the harness.
Internal failure of the bank 2 upstream oxygen sensor.
Moisture or corrosion in the connector.
Rich mixture on bank 2 from a leaking injector on that side.
Rich mixture on both banks from high fuel pressure or an EVAP purge valve stuck open.
Engine computer fault (rare).

How to diagnose5

Compare fuel trims between banks; if only bank 2 is strongly negative, look for a leaking injector on that side.
Unplug the sensor and watch the reading; voltage staying high with no sensor means a wiring or computer fault.
Inspect the connector for water or corrosion bridging the terminals.
Measure fuel pressure against the manufacturer specification if both banks run rich.
If the wiring and mixture are fine, replace the sensor.

How to fix4

Clean the connector and repair any shorted wires.
Repair the leaking injector or the cause of high pressure if found.
Replace the bank 2 upstream oxygen sensor if it is proven faulty.
Clear the codes and confirm the signal switches normally once the engine is warm.

Repair cost

0–500

500–2,000

2,000–5,000

5,000+

In Saudi riyals; the highlighted part is the expected range for this fault.

A connector or wiring repair is cheap, a new sensor costs more, and the upper end is reached when an injector or pressure regulator must be repaired.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions

Does the code mean the engine is burning too much fuel?

Not necessarily. The mixture may be fine and the high voltage caused by a short or bad sensor; the fuel trims show which one it is.

Why is there no matching code on bank 1?

Because the fault usually belongs to bank 2 alone, such as its sensor, wiring or an injector on that side, which helps narrow down the cause.

This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.

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