Q: Can't pass emissions.

asked by on January 07, 2016

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.

Catalytic Converter Replacement $288.41 - $1959.69 Get a Quote

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.

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Truck shakes, sputters, and loses power when accelerating.
Hello, I would enlist the help of a mechanic to inspect the engine (https://www.yourmechanic.com/services/engine-hesitates-during-acceleration-inspection) because this problem could be a number of things. I would do a tune up on it's spark plugs, air filter, fuel filter and then go...
Van shut off while driving, now it won't start
The vehicle may have had a problem with a computer sensor like the crankshaft sensor (https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-crankshaft-position-sensor) or camshaft sensor (https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-camshaft-position-sensor) but normally they would have put a code into the computer. This is not a common problem and would need...
engine rebuild
Hi there. Our "How to" articles (https://www.yourmechanic.com/article/how-to-rebuild-a-car-engine) are written as usually general guidelines - not specific instructions that apply to a particular vehicle. We don't specify the precise steps for completing any repair because the reality is that every vehicle...
Code p0008
This is a general code associated with vehicle timing which can be caused by many different things such as: Engine timing out of sync Worn timing components (chains, gears, guides) Crankshaft or camshaft sensor malfunctions Wiring damage ECM software out...
My 2002 Ford Crown Victoria is acting like it want to go, even though I'm not pressing on the gas
Hello. The most common cause of the high engine idle accompanied with a delayed acceleration will be a vacuum leak in most cases. This engine gets vacuum leaks (https://www.yourmechanic.com/article/is-it-safe-to-drive-with-a-vacuum-leak) on the vacuum connection on the intake manifold (https://www.yourmechanic.com/services/intake-manifold-gaskets-replacement) for the...
Bcm replacement
If you are certain that the BCM has failed and you intend to get one from the junkyard anyway, I would recommend simply giving it a try. If it works, problem solved. If it does not work, it is very...
How much would you charge to replace the control arm bushings in the front and rear? 1999 Mazda Miata
Sent to CS front lower control arm bushings replacement front upper control arm bushins replacement rear lower control arm bushings replacement rear upper control arm bushings replacement
When I drive my car is fine but when I hit a bump in the rode it shakes and swerve a little. What can that be?
You could have bad lower ball joints on the lower control arms. You should have entire front suspension checked for worn loose components.
My 2007 Nissan Altima is not accelerating properly... when I punch gas the rpms go up but the car doesn’t accelerate
It sounds like a problem with your transmission. It may not be shifting out of first gear. This could be due to any number of issues but may have something to do with the check engine light on your dashboard...

Related articles

P2442 OBD-II Trouble Code: Secondary Air Injection System Switching Valve Stuck Open Bank 2
P2442 P2442 code definition The P2442 code is a generic powertrain code related to the auxiliary emissions control system. This particular code appears when the bank 2 secondary air injection valve stays open. The P2442 code is also related to:...
P0291OBD-II Trouble Code: Cylinder 11 Injector Circuit Low
P0291 P0291 code definition When your vehicle’s PCM registers the P0291 code, it means that a voltage reading came from the fuel injector circuit – for cylinder number 11’s fuel injector – that doesn’t conform to the predetermined value referenced...
P0966 OBD-II Trouble Code: Pressure Control Solenoid B Control Circuit Low
P0966 means a problem related to the pressure control solenoid valve which may cause problems shifting gears, harsh upshifts or shock upon upshifting.