Skip the auto shop - Our mechanics make house calls

Q: Code P0158 after sensor swap

asked by on

I had a code P0420. After speaking to multiple parties, I decided to replace my O2 downstream sensors (as my FlashPaq reader told me it was a downstream problem). I replace the passenger side, and the sma score came back. Now I've replaced the driver side, and I'm seeing code P0158 high-voltage something-or-other. How do I fix this? Where do I go from here? Do I need a new catalytic converter? I'm trying to fix this problem without taking it in and paying a bunch of money, but I don't know how to proceed. Thanks, Johnny

My car has 56000 miles.
My car has an automatic transmission.

A: Hi, thanks for writing in. I suspect your &...

Hi, thanks for writing in. I suspect your "upstream" sensor is the primary problem, and should be replaced. The downstream sensor you did replace is really measuring whether the catalytic converter (the main cat, not the pre-cat) did the job to clean things up. But the upstream O2 sensor does the heavy-lifting to tell engine management to lean things our, making the catalytic converters job easier. There is also a Jeep Customer Satisfaction program (CSC-10042886-7723) to re-program the software for the downstream O2 sensor to check more often under certain circumstances when the down stream sensor becomes slower to respond (as it ages). I recommend checking with Jeep for the Customer Satisfaction O2 Sensor reprogramming.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Car stalls when coming to a stop

This sounds like an airflow issue. Either the intake air is not being measured properly on deceleration, or the throttle is not adjusting air properly (i.e. the throttle motor or position sensor). Fault codes should be read out of the...

Q: Car bucks going up hill

When your vehicle climbs a hill, the additional stress is sometimes too much for it to handle. Judging by the "bucking", it seems the engine is struggling to combust the air/fuel mix in the cylinder. This can be due to...

Q: Leak near front passenger wheel possible axle shaft seal

Hello, thank you for writing in. The location that you describe sounds most like a broken axle seal. While it is okay to drive the vehicle for the immediate time, that oil will collect dirt and debris and clog the...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.