everytime after speed up. speedometer gauges drops to cero and five to ten seconds after an intermitten light comes off (D4). at the same time the engine acelerates a little more. it some times works perfectly with no problems. I appreciate any help.

 

You did'nt mention what year, but I suspect the VSS (Vehicle Speed Sensor) is about to take a powder. See if you can pull a code (etc) to confirm

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It is a Honda Accord 1993. but for what kind of code am I looking for? it also "check engine" turns on when I exiting the freeway. could be the oxigen sensor?

 

The "Check Engine" light will flash codes when the ECM is interogated. (the system is recognizing a problem, and has set a code in memory). I believe AutoZone offers a service (they'll pull the code for you), so you'll hopefully buy from them. (if you don't know how to do it yourself.

 

If you have a short wire or small paper clip, you can get the "flash" code.
http://members.troublecodes.ne...n.jpg
Then you can repost to find the codes meaning, and have an accurate diagnose.

 

This may have some relevance.
If you've Adobe Reader in your computer, you can download this.

Try this
http://www.google.com/search?h...earch
It should be on the top of the page, with this across the bottom:
hondainfo.hottamale.hu/manuals[/url]/ Honda%20tech2tech/chpt_03.pdf

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