2000 Honda Accord engine RPM fluctuation

Tiny
KHLOW2008
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If the CEL is not showing and no other noticeable problems showing, I guess there is nothing to worry about.

My guess is that he has done some adjustment to the IAC.
The problem with some people is the they worry someone would steal their secret.
Maybe they would rather bring it to the grave let others know how they did it.
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Friday, August 29th, 2008 AT 1:09 PM
Tiny
IAMFURQAN
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At last I have a clue what he had done. I was inspecting my engine for any clue what that mechanic had done when I noticed that my oxygen sensor was actualy not connected rather it was engaged so that no body would notice it is disconnected. I imidiatly called that mechanic and ask if I should connect it, he forcefully recomend me to not connect it back otherwise my car will start bevaving same like earlier. He said that sensor was bad and he had made arrangement and reprogrammed the computer to ignore it thats why car is running ok know. He is still not telling me any thing else. So what do you think, what actualy he had done. Kindly tell me the roll of oxygen sensor in this problem.
Thanks once again.
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Saturday, August 30th, 2008 AT 11:01 AM
Tiny
KHLOW2008
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Does the Check Engine Light show for 2 seconds during initial ignition On?

Honda PCM are non programmable unless he has replaced the chips. I don't understand what he is bs about.

Get a scan done and see if you can find any error codes, don't reconnect the O2 sensor first.
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Saturday, August 30th, 2008 AT 11:25 AM
Tiny
RASMATAZ
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The role of the Snitcher ( Oxygen Sensor ) is like a heart monitor for the engine's air/fuel mixed when in the closed loop operation. When disconnected it will have a low reading and computer will constantly adjust for fuel making it run rich.

HOW IT WORKS

The O2 sensor works like a miniature generator and produces its own voltage when it gets hot. Inside the vented cover on the end of the sensor that screws into the exhaust manifold is a zirconium ceramic bulb. The bulb is coated on the outside with a porous layer of platinum. Inside the bulb are two strips of platinum that serve as electrodes or contacts.

The outside of the bulb is exposed to the hot gases in the exhaust while the inside of the bulb is vented internally through the sensor body to the outside atmosphere. Older style oxygen sensors actually have a small hole in the body shell so air can enter the sensor, but newer style O2 sensors "breathe" through their wire connectors and have no vent hole. It is hard to believe, but the tiny amount of space between the insulation and wire provides enough room for air to seep into the sensor (for this reason, grease should never be used on O2 sensor connectors because it can block the flow of air). Venting the sensor through the wires rather than with a hole in the body reduces the risk of dirt or water contamination that could foul the sensor from the inside and cause it to fail.

The difference in oxygen levels between the exhaust and outside air within the sensor causes voltage to flow through the ceramic bulb. The greater the difference, the higher the voltage reading.

An oxygen sensor will typically generate up to about 0.9 volts when the fuel mixture is rich and there is little unburned oxygen in the exhaust. When the mixture is lean, the sensor output voltage will drop down to about 0.2 volts or less. When the air/fuel mixture is balanced or at the equilibrium point of about 14.7 to 1, the sensor will read around.45 volts.
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Saturday, August 30th, 2008 AT 4:50 PM
Tiny
IAMFURQAN
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Hi rasmataz,
thanks for your information regarding O2 sensor. Can you suggest me the roll of it in my case history. How come a bad sensor have been bothering me so much my car was running with so much fluctuation that it was almost imposible to drive it. Now mechanic has disconnected my O2 sensor and it is running ok and he is insisting my car will consume less fuel and I have also noticed it is consuming lot less fuel now.
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Wednesday, September 3rd, 2008 AT 1:05 AM
Tiny
RASMATAZ
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Sound like the problem is a lean mixture and computer compensating by throwing fuel at it. When an oxygen sensor is disconnected/contaminated/out of range the air/fuel will be rich at all times.

You need to test the voltage to the oxygen sensor-could be a wiring problem or computer
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Wednesday, September 3rd, 2008 AT 3:44 PM

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