I own a '97 EX Coupe (production date December 1996) with 95K which has been dealership maintained since I purchased it, new.

The car is at point where things are starting to go wrong and the dealership doesn't seem interested in doing the work. The car is a good, reliable car and I want to keep it, even though I am looking into a new one.

My check engine light came on back in November. The computer is reporting a 402 code. At first I thought I would just get used to the light being on. Recently, I clocked my gas mileage and found it to be down to 22 mpg from 34. Clearly, there is something that needs to be addressed.

I have the original tech manuals along with an easier to follow Chilton manual because I want to become more proficient in fixing/maintaining my Civic.

I don't mind spending the money to keep the car running well. What I hate is spending money on a part that ends up NOT being the problem.

I'd like to hear from people who have had this error code. I'd like to understand what troubleshooting steps you took to identify and fix the problem.

 

Usually you can find the codes in your Chilton manual in the emissions section.

 

disconnect the plug and vacuum supply hose from the EGR valve.

start the engine, put it in neutral, set the parking brake, and allow it to reach operating temp (the guage needle should be over the C line, maybe around 1/4 way up)

hook a vacuum tester pump apply 8 in. Hg of vacuum to the EGR valve nipple

if the idle speed drops more than 100rpm and returns when vacuum is released, then its ok.

if it doesnt drop more than 100 rpm, then try cleaning the valve and inspecting it for any blockage. if that doesnt fix it, then try replacing it.





this is what i got from Chilton (a Prelude one is the only one i had in front of me, but it should be almost identical.)

if you plan on working on your own car, then you will need a few tools.

a basic ratchet/wrench set (metric) aprx $10-$50
compression tester aprx $15-$30
Vacuum tester aprx $10-$30
Timing light $15-$30
and a GOOD floor jack and jackstands. stands-$20-$30 and spend at LEAST $100-$250 on a jack. you will be mad that you used a crappy $30 jack when you are trapped with your hand smashed between the fenderwell and the standing tire and have to just stand there with the weight of the car on your hand (or worse) while your wife/GF/friend runs for help to lift it off of you. trust me.

and good luck. once you start working on your car, you will love the feeling you get of taking a car with a problem, and making it work right. its addictive.