Rep Power: 0

Hey guys. I have a 1993 Honda Civic Lx manual with the 1.5L soch. Im only getting 240 miles on a tank of gas, and im trying to figure out why Its not better. So here is what I have done already, new fuel filter, new plugs, new wires, new cap & rotor. The air filter is clean, It idles fine and seems to run fine. Any suggestions? thanks.

 
Rep Power: 234

It's running rich. Why is it running rich you say? Many reasons but, the first one that comes to mind is the O2 sensor is going bad and putting fuel trim out of whack. Try replacing the O2 sensor, #6: http://www.hondapartscheap.com/south...t=0&quantity=0

 
Rep Power: 0

Woah! 160 bucks! could I get away with this insted... http://www.autozone.com/autozone/par...5&sortType=low

also, If the O2 sensor was infact bad, wouldn't that make the check engine light come on?

 
Rep Power: 217

You have a 1993. ODBII wasn't introduced onto most vehicles until around 1996, so that's why. Lazlong is on the right track though. Computer is getting the wrong signals and the O2 sensor is saying there isn't enough fuel being delivered, so when the next time it goes back, the PCM ends up dumping more fuel into the system.

 
Rep Power: 234

Yeah, sorry, should have warned ya about the price. The cat converter is even more.

For the most part nobody has had any luck with those sensors on Hondas, they either don't work or fail quickly. I would recommend OEM when replacing sensors and cats. Sorry to be the bearer of bad news.

You can check for CELs but, I don't know the method. Somebody help this guy out.

 
Rep Power: 217

http://honda-tech.com/showthread.php?t=1901557
The only problem with that is that you actually have to have the CEL pop up from what I read. My Corolla had its O2 sensor fall off and I never got a code. I mean, you can try that method as it won't hurt anything by trying.