I just got a used 2005 Accord from the US recently and discovered the Check engine lights and maintenance required lights. Also, I always percieve a bad smell (not burning) each time I try to speed. This though has not affected the car perfomance but has increased my fuel consumption. Can anyone help out?

sounds like ur O2 sensors are bad , but pls get it diagnosed to know the real problem

The catalyst in your catlytic converter, AND / OR the oxygen sensors are deteriorating. This is caused by the lesser quality of fuel being used on our side of the globe. Due to the malfunction of the converter the oxygen sensors before, and after the converter, are most likely carbonized: hence unable to give proper readings of the oxygen content in the exhaust, after the vehicle has entered closed loop (this is when the Electronic control module acts on readings from the oxygen sensor to adjust fuel curve for maximum effeciency ONLY after the engine has reached opearting temperature. In open loop the oxygen sensors are ignored by the ECM, as on a cold start condensation will form on the intake manifold, so more fuel, and air are required to quicikly atomize the denser air/fuel mixture, and get the motor heated up faster to its operating temperature.
If accurate readings are not sent back to the ECM; hence it does not know what to do, and opearates in a failsafe mode by increasing the injector duty cycle, and dumping more fuel into the engine. This is by default, so that the vehicle may still be used, until rectified, but at a price, INCREASED FUEL CONSUMPTION!
The vehicle will require a diagnostic scan. The code you will receive is catalyst, heater circuit, or oxygen sensor failure.
You may leave the catalyst, as it's purpose is to reduce emissions out of the tail pipe. As long as the quality of fuel we are using here is sub-standard, a catalytic converter will never function efficiently, and will certainly deteriorate, if replaced.
Although, replacing the oxygen sensor / sensors will aid in better fuel economy.
I would also recommend a fuel injector cleaning, testing, intake manifold flush, throttle body service, and fuel pump casing filter service. This will improve your fuel economy, might not be 100% due to the malfunctioning catalyst, but you will definitely notice a significant difference.
We can assist you on this, if you require. Kindly contact us on the following nunbers:

HAMA ENTERPRISES LTD.
08026158430 & 08098045555

Hope the above information comes useful to you.

Best regards

I have confirm that my problem is the O2 sensor but where can I buy a new one men?

Asernal4va, men can you help me with this sensors?

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For a 4 cyl, its ~$70+tax, based on a web search(Bosch).
Call a friend in US, give your vehicle spec and place your order.

How did you know its O2 sensor?
What was the code(s) you got?

The mechanic ran a software programme while the engine was running and it diapyed that the Oxygen sensor malfunctioned in bank 1 and 2, he further used two other instruments and then confirmed that is was the O2 sensor and the the catalytic converter. Meanwhile mine is a V6 and I need the 2

For a V6 its Bosch 15401(2) @ $90 each+ tax
Your Acoord mmust be over 100k miles old.

http://www.autozone.com/autozone/catalog/parts/partsShelf.jsp?displayName=Oxygen+Sensor&currentPage=1&categoryDisplayName=Emission+Control&navValue=16000117&itemId=117-0&parentId=60-0

There is Denso part too for same price.

No it is just 56k miles, was bought in Dec., 2007 at Atlanta had a minor accident in december 2008 sold to in May in Auctions