P0133 on a Jeep: Causes, Fixes & Repair Cost

🟠 Moderate severity · drivable

A Jeep with P0133 usually still runs, but fuel economy drops a little until the sensor is replaced.

What P0133 means on a Jeep

On a Jeep, P0133 means the bank 1 upstream oxygen sensor is switching too slowly. This sensor sits in the exhaust before the catalytic converter and helps the computer keep the fuel mixture on target.

Is P0133 common on Jeeps?

P0133 is common on Jeeps like the Wrangler, Grand Cherokee, and Cherokee as they age. The upstream sensor wears out over time, and an exhaust leak at the manifold is a common extra cause, especially on older inline-six models.

Commonly reported on: Wrangler, Grand Cherokee, Cherokee, Compass.

Symptoms

Check engine light on
Slightly worse fuel economy
Rough idle or hesitation
Failed emissions test

Common causes

most common: Aging upstream oxygen sensor (bank 1, sensor 1)
common: Exhaust leak at the manifold
common: Sensor contaminated by oil or coolant
less common: Wiring or connector damage

How to fix it

Fix	DIY?	Typical cost
Inspect the exhaust manifold for leaks before replacing the sensor	Yes	$50–150
Replace the upstream O2 sensor	Yes	$80–220
Repair the sensor wiring or connector	Mechanic	$100–250