OLIVAHEC

Can someone please point me in the right direction?
I have a 94 Si that is throwing a #12 code on the cel, EGR.....
I did the old "suck on the vacum line test" and the engine stalled. from what i understand this indicates that the EGR is working properly.
What is my next step? all the lines look good too. would it be the EGR solonoid?
Please help, that little yellow light is really annoying!!!!!!!!
Thanks...............Hec

OLIVAHEC

Now I know there has to be someone who has been through this at least once..........little help here

Redline

Alright bud. I've got a '96 Si which had the EGR ports clog not to long ago. You'll notice a severe loss of power. EGR ports become clogged with carbon over time, but the lost is sudden. Ports can be cleaned (they don't have to be replaced, so if you take the car to the shop, you'll be paying for maybe 3 hours of labor.

If your EGR ports are being clogged, maybe its time to check up on other high-mileage maintaince. The more preventable stuff, like time-belts and water pumps.

Let me know how it turns out.

Tola

My manual is in the garage right now, but I remember reading over the EGR section several times. If I remember correctly, if your engine stalls with the vacuum test, it could be your solenoid. You could just replace the spring in there. I received a very detailed answer the last time I asked this question I got a very good reply from someone (I forgot his name):


"I'm not sure what car you have and if it's drastically different from my
old 2Gen 87 Prelude Si but EGR control vacuum won't pull vacuum at idle
so you won't feel anything on that vacuum line. You need to get the
engine up somewhere between 1500 and 3000 rpm and hold that rpm very
steady within that range for several seconds in order to pull EGR
vacuum. It may take as much as 10 seconds for you to see or feel vacuum
being pulled on that vacuum line.

One thing that was common on my particular Prelude generation were two
things; on that car and many Hondas there was a box mounted on the fire
wall where many of the vacuum lines went into. Inside that box were two
things for the EGR valve. There was a little white canister where 3
vacuum lines attached. This canister had a little passage way that
would get clogged sometimes. A thin piece of wire was all that was
necessary to clean it out. I never had the canister plug up but that was
reportedly a common problem.

The other thing that would go bad was the EGR control solenoid. That
too was located inside the box on the firewall. If I remember right it
connected to that little canister that I mentioned previously with a
short section of vacuum line. What happens is the spring inside the
solenoid breaks. Now if your car is similar to my old Prelude I would
look at the canister and this solenoid. You can check the solenoid by
applying vacuum and 12 volts to the solenoid. If it's working properly
you should be able to turn on and off any vacuum when you apply and
remove the 12 volts. If the solenoid allows vacuum to pass or not to
pass regardless of 12 volts applied the solenoid is bad because the
spring broke or it's burned out and the valve is eithe stuck open or
closed. A good solenoid will click rather loadly and you should feel
the click when you apply 12 volts to it. If you get a faint click or you
can't feel it click the solenoid is bad. If you shake the solenoid valve
and it rattles, that's an indication that the spring is broke too. You
can identify the solenoid valve easily. It should connect to the little
with canister with 3 vacuum lines. The solenoid valve also has a pair
of wires going into it.

On my 87 the solenoid broke once and it cost something like $100 for a
new one. Rather than spend $100 on a $10 part I took the solenoid apart
and put a spring in from a ball point pen.

If either of the above pass the tests then it's almost safe to say the
EGR valve is bad or the problem is down by the EGR valve. It's also
possible that the EGR valve maybe stuck because of carbon build up.
Simply remove the EGR valve and look where the EGR valve pintel goes
into. If you see a carbon build up and it's impeding the movement of the
EGR valve you'll need to clean out the carbon. And if you have a vacuum
pump handy apply vacuum to the EGR valve to see if it operates.

I'd start by checking the solenoid control valve and the little canister
on the EGR vacuum circuit (provided it is similar to my 87 Prelude). I
have a feeling that's where your problem lies."

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-94 VTEC
-98 M3