Skip the auto shop - Our mechanics make house calls

Q: Code p0140 we replaced 02 sensor and catalatyic converter

asked by on

We replaced the catalatyic converter and the back 02 sensor and we checked the wiring for 12 v it's all good
My car has an automatic transmission.

The vehicle should have an original equipment HO2S not aftermarket generic. For a P0140 code, the wiring harness should be closely inspected for damage: chafing, pinches, melting, or water intrusion into connector. Exhaust leaks upstream of the HO2S must be eliminated as that can also cause this DTC. After all other possibilities have been eliminated, the PCM may turn out to be the root cause. An experienced mechanic performing scan tool diagnostics would be recommended at this point. A technician from YourMechanic can come to your home of office to thoroughly diagnose your Check Engine Light and make the correct repairs.

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

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: My fam stays on after I turn the car off and it runs hot in 15 minutes what should I do

Hello, thank you for writing in. The engine cooling fans are known to stay on when the engine needs help cooling down. While we cannot rule out the fans just yet, you want to check for the other possible causes...

Q: Engine swap

Hi there: Sure; both engines are compatible with either 2002 or 2004 Pontiac's. Just be sure that the mechanic gives the vehicle back to you without any starting issues; as this tends to be a problem if the mechanic does...

Q: My 2005 Aztek, streei g wheel shakes a little and make a slight rough sound when sitting at lights, stop signs. What may it be?

There are two initial possibilities: 1) worn or faulty motor mounts; and 2) an engine management problem such as a fuel or ignition system fault. If you do end up replacing motor mounts, genuine OEM mounts are recommended in order...

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...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
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...