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OK I bought my first Honda. its a 94 Honda civic lx 5 speed. Cherry car 160,000 original miles on it, runs great ice cold ac, but the check engine light is on and i'm only getting about 28 mpg. I've been told it could be the o2 sensor making the engine run a little rich. Any suggestions?

 
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funny to read this 2 days after my check engine light came on for the first time...

what?! complaining about getting 28 mpg?! lol really though, this car is estimated at 29-36. check the link http://www.fueleconomy.gov/feg/noframes/10744.shtml

maybe you are driving her a little harder than gramps did to get this estimated mpg?

and on the check engine light issue, i'd get it scanned to see what codes come up. auto zone does free scans or auto shops can do it also with a better scanner, that might cost you though compared to auto zone being free. yes, an o2 sensor can make your car run rich, reduce gas mileage a little bit, and make the check engine light go on. so maybe and hopefully you're right and it is the o2; i am hoping the same thing for my car. good luck

 
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that's what i'm going to do first and autozone and advanced and oriellys can't read a 94 its the 5th gen i guess it doesn't have the cpu port under the dash i've been quoted 80 bucks to get it checked so i'm gonna shoot for the 50$ part and it that fails i've got a new o2 sensor

also there has been an unusual amount of heat radiating from the center console i where the cat is from i wonder if it needs to be replaced.... any info on that

 
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i would say if the heat is great enough that you can feel it through the center console, that your cat is definitely clogged. the filling inside of the converter brakes/comes loose over the years and begins to fall to close the chamber where the exhaust should be flowing, rather that being trapped.

if i were you and you have the money, put a cat converter and an o2 sensor on it. i'd bet you guessed right and the heat you feel is a clogged converted; and the rich fuel could very well be an o2 sensor.

those are my first guesses; other than that it could be mass air flow sensor, bad plugs, coolant temp sensor tricking the computer, etc. etc. it might be in your best interests to get it scanned at a shop and pay the 50.. but i think the o2 sensor and cat will fix your problems personally.

post back and let us know what you find out! good luck!

 
Rep Power: 194

Pull back the carpet on the passenger side kick panel. The computer is there. Determine the sequence of the lights and that will tell you the code.

 
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how do i get the cpu to spit out a sequence

 
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Sorry I wasn't clear. Here are instructions with pics taken from Honda Tech.

Check engine light OBD1

 
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hey, same thing happened to my 93 civic lx. My idiot brother never got around to replacing the O2 sensor when the check engine came on. I got the car from him when it had been on for like 5 months. I finally changed out the O2 sensor but it was too late. My cat went a few weeks later.

So my best bet is that your cat is messed up because you don't know how long the O2 has been bad. As you know, the O2 controls the richness of the fuel and a bad O2 will make the Cat burn incorrectly and cause it to fail.

Change the O2 asap and hope for the best. It's easy, you can see the O2 sensor right behind the radiator. Also we only have one O2 sensor so very easy to change. Borrow the O2 part kit from Advance Auto or Autozone.