Q: Can't pass emissions.

asked by on

My car's Check Engine light comes on and a cannot pass an emissions test. I had it diagnosed and it said the catalyst efficiency was below threshold in bank 2. The mechanic said the probable causes were a leak in the exhaust before the converter, a faulty heated oxygen sensor in bank 2, a rich fuel to air ratio, or a faulty catalytic converter.

The system should be scanned and the 02 sensors checked when the system is enriched to see if the sensors respond correctly. You could just have a defective sensor or a convertor that is bad. Only these tests can determine which one is the cause.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Can't pass emissions.

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: Q: Check Engine light; catalytic converter

When a catalytic converter begins to fail, the computer will give a reading of the code P0420 and/or code P0430 which pertains to catalyst efficiency. The catalytic converter is, in a way, like a metal filter that traps toxic gases...

Q: Steering wheel locking. A recurring problem.

Steering issues on any car is a most serious concern, but this is especially so when the steering wheel locks or binds. There is a Technical Service Bulletin, information directly from the Kia dealership for this vehicle that deals particularly...

Q: I have a whining squealing noise coming from somewhere in my pulley system and serpentine belt.

If the noise changed when the battery was replaced, I would first suspect the alternator. Sometimes, when a bearing/bushing starts to go bad it will only make noise with the belt installed, as the tension can cause pressure to be...

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 Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...