OBD-II Code P1195 — What It Means & How to Fix It

What Does This Error Mean?

P1195 means Heated Oxygen Sensor Slow during Catalyst Monitor — Bank 1, Sensor 1. During the catalyst efficiency monitor test, the PCM watches how the upstream oxygen sensor behaves. If the sensor is too slow to respond during this test, the catalyst monitor cannot complete and P1195 is set. This code is especially common after oxygen sensor replacement with an aftermarket part that does not respond as fast as the OEM sensor. You may also see this code when an oxygen sensor is simply aging and losing response speed.

Affected Models

Common in Chrysler, Dodge, and Jeep vehicles with Mopar PCM O2 monitoring
Common in Jeep Grand Cherokee, Wrangler, and Liberty
Common in Dodge Ram, Durango, and Dakota
Common in Chrysler 300 and Pacifica with Chrysler OBD-II monitoring

Common Causes

Aftermarket oxygen sensor with a slower response time than the OEM specification requires
Aging oxygen sensor with a degraded sensing element losing response speed
Failed oxygen sensor heater causing slow warm-up and delayed activation
Exhaust leak upstream of the sensor causing dilution and inconsistent readings
Contaminated sensor element from oil consumption or coolant intrusion

How to Fix It

If an aftermarket oxygen sensor was recently installed, this is the most likely cause. Replace it with an OEM Mopar sensor or a known quality equivalent.

Chrysler's PCM has strict O2 sensor response requirements. Many generic sensors fail the catalyst monitor even when technically functioning.
Use a scan tool to monitor O2 sensor switching speed. Time how quickly the sensor oscillates between 0.1V and 0.9V during closed-loop operation.

A healthy sensor should switch at least 5 to 10 times per second at operating temperature.
Check the O2 sensor heater function. Measure heater circuit resistance — it should be within the range specified for the sensor.

If the heater is not working, the sensor takes much longer to heat up and respond correctly during the catalyst monitor test.
Inspect for exhaust leaks at the manifold, flex pipe, and manifold-to-pipe junction. Listen for ticking sounds during a cold start.

Spray water on suspect areas while idling — sizzling or steam near the manifold confirms a hot exhaust leak.
Replace the oxygen sensor with a high-quality or OEM equivalent. Clear codes and complete the official OBD-II drive cycle for the catalyst monitor.

The catalyst monitor requires specific driving conditions — sustained highway speed followed by deceleration — to complete on Chrysler vehicles.

When to Call a Professional

Oxygen sensor replacement costs $150 to $350 per sensor. An OEM Mopar or equivalent-quality sensor is recommended for Chrysler products. Exhaust leak repair is $100 to $400. This is generally an affordable repair — the challenge is diagnosing the cause correctly.

Frequently Asked Questions

Why does P1195 appear after replacing my oxygen sensor?

Aftermarket sensors often have a slightly slower response time than the original OEM sensor. Chrysler's catalyst monitor is strict about sensor response speed. If the new sensor is not fast enough, P1195 is set even though the sensor is technically working. The solution is to use a higher-quality or OEM sensor.

Can P1195 cause me to fail emissions?

Yes — P1195 turns on the check engine light. A lit check engine light causes automatic emissions failure in most states. Also, if the catalyst monitor did not complete, that alone may cause a failure depending on your state's rules.

Is an OEM oxygen sensor worth the extra cost?

On Chrysler vehicles, yes. The Mopar PCM has tight tolerances for O2 sensor response. A quality OEM or Bosch premium sensor avoids repeat visits for P1195. The small cost difference is worth the peace of mind.