I just purchased a 1997 Honda Civic DX coupe with 176,000 miles, it is a manual trans. The body is in great condition but the interior was a pig on the inside. Last weekend I removed the front seats and carpet and cleaned them. I also cleaned inside the engine compartment with a scrub brush and a bottle of Westley’s Tire White, I did cover the alternator with a plastic bag to keep the water out. I scrubbed the underside of the hood and did a general cleaning under the hood so things did get wet. Other things I did to the car: I replaced the front pads and rotors, rear drums and shoes, I had the passenger side axel shaft rebuilt because the boot was torn. I changed the oil and noticed that the oil was really orange in color and replaced the air filter

When I bought the car the Check Engine light was on and I was told the previous owner took it in to a Honda dealer and said that one or both of the O2 sensors would need to be replaced. I was told that if I wanted to clear all of the stored codes and turn off the Check Engine light that I would have to remove the + and – cables from the battery and touch them together to clear the stored codes. That did work, the Check Engine light is no longer on.

Last night after finishing all of my improvements I started the car and rolled it out of the garage and let it idle and warm up in the drive way. After about 10 minutes of idling I heard either pop sound or knock sound. Shortly after that the car would idle way down for about 2 seconds and then idle back up to normal for about 7 seconds. This up-down idle would not stop. I took the car for a short ride and when I pulled back into the driveway the up-down idle continued on. The Check Engine light did not come back on.

I know that this is a long one to read but I wanted to list everything that I did to the car.

Can any one give me any suggestions on what I can do to fix this problem?

David

 

Drive for a few days normally commuting, shopping, etc. The computer needs to recalibrate (basically retune itself to the engine) after being reset like that. If the light comes back on, pull the code and if it is an oxygen sensor, replace the sensor. A bad oxygen sensor will hurt your gas mileage and can cause trouble with the catalytic converter later if it hasn't already.

 

How do I pull the code? Do I take it back to the dealer to read the code? And how do I define the code once I have it, is there a web site defining the codes?
David

P.S. Thanks for the reply!

 

https://www.hondacivicforum.com/m_152006/tm.htm

 

ya so mine does the same thing but i have been driving mine for like 10 months now and it hasnt changed... so should i reset the ecu by putting the + and - together... and where do i do that... the end that was connced to the battery or the other end of the cords

 

if you reset the ECU, the code will disappear for a while, until it has done enough cycles and then the CEL will come back

 

so how do i reset it though

 

If you have an DX or CX Civic you can clear the "Check Engine" codes from the computer by removing the + and - cables from the battery and hold them together for at least 60 seconds and then reconnecting the + and - cables back up to the battery. I did that on my civic and the light went out. It will not work on an EX or LX I am told.

I have about 35 miles on my civic since I cleared the check engine light codes and it still goes up and down. The "Check Engine" light has not come back on since.

When the car is cold it idles fine but when it reaches operating temp the idle goes up and down. Also, after it warms up and the idle goes up and down I can stop the up-down idle by letting the clutch out a little to the point where the car starts to move. So I take it there is a switch on the clutch, because the starter will not engauge when I am trying to start the car with the clutch in the up or out position.

If any of you have any suggestions I can test your idea because I also have a 1996 honda civic and I can use the parts from that car to test with a different part into the 1997.

I am really stumped on this up-down idle problem and could really use your help, I did not want to have to take it in to the Honda dealer to get this fixed, I wanted to fix it with out dropping a ton of $.

David

 

Any help?

 

I could be wrong, but wouldn't touching the positive and negative together possibly fry something? I have an 88 civic and i simply pull the hazard fuse from under the hood and leave it out for about 15 minutes and that would reset everything. About the idle, in my car it was the idle air control valve. It went bad and also revved up and down. From Honda, the part costs about 350.00 A good first place to look is a junk yard or parts place.I hope I was able to help.