jfarrell289

I have a 97 Civic EX V-TECH manual and the check engine light is on, the codes that it was throwing was that cylinders 1 and 3 are misfiring and that the idle control mod was bad. I know the cylinders are not misfiring, pulled the plugs one by one...
I have replaced; all spark plugs and wires, idle control mod, fuel filter and both O2 sensors.
I am at a loss, the light is still on throwing the same codes, nothing I have done has helped me.
The car idles strange too... when in neutral the car will bog out and drop out and almost die then it will pick right back up again and purr like a kitten...
I cannot afford to take it to a shop and have them charge me thousands to fix it...
Help?! I love this car and don't want to let it go but if I cannot fix the issue I'm going to have to sell her...

themow

Did you run a compression check? Also if you can find a new ecu cheap, try that. It was the problem on my 97 that I could not figure out for the life of me.

HondaPartsHero

Did you clear the codes to see if they come back?

SpokaneSpeed

Don't EVER tell someone to clear codes unless they feel they've fixed the problem. You're basically throwing all the good diagnostic information in the trash, and making the next technicians's job even harder.


Spark test is where I would start, followed by compression. Post your results.

jfarrell289

I have run a compression check and it's all normal, is it possible that my ECU is fried? What was your civic doing when you decided to change out the ECU on yours?

jfarrell289

I would never clear codes, I'm going to have them read again tonight, I have done a spark test and there is nothing wrong there... I'm just getting down to the wire, I have emissions in Sept. that I need to pass to keep my baby on the road... I'm at a loss and don't want to give up but I'm running out of time and money

grumblemarc

iTrader: (4)

It's a common practice. Codes indicate current issues. If you clear the codes and they come back, no harm no foul. If some never come back then they aren't issues are they?

HondaPartsHero

I guess the Honda service manual should be thrown in the trash then as its ALWAYS the first step after reading the code. I agree you should check the codes first but intermittent issues can and do exist, a lot of times in the area of misfires (bad gas, water intrusion, etc).

IE "Do the ECM reset procedure"

jfarrell289

What will resetting my ECU hopefully do?

HondaPartsHero

If your car is running bad then it will still run bad after you clear them but it may help pin point your issue as there may be some codes that are already fixed.

jfarrell289

Okay I had the code reset because it was a part I recently replaced. 3 days later it has come back on, the code now is P0505... I have no clue what to do at this point. I've replaced the idle control mod... it has an after market air intake... any other suggestions??

silkypillows

you most likely have a vacuum leak after the throttle plate.

cracked vacuum hose - open/disconnected vacuum port - leaking gasket -idle set/air mix screw tampered with - are a few potentials. low coolant/air in cooling system is a possible cause as well, but it's unlikely to pull a p0505.