Honda Civic VX failed NOx, EGR system not working
 

Honda Civic VX failed NOx, EGR system not working

I have a 1992 Honda Civic VX (Calif model). I am having problems
passing a smog check because NOx values at 15MPH are too high. I know
the problem lies in my EGR system. The EGR valve is not opening
because the EGR solenoid valve does not receive a signal from the
computer (ECU). I have verified the operations of the EGR valve and
EGR solenoid by jumpering a direct wire to the battery. When I do
this the EGR solenoid and EGR valve opens and everything works great.
I do NOT get any Check Engine light to help me narrow down the
problem. Any help is greatly appreciated.

Could you find which pin on the ECU operates the EGR control box and run a jumper wire between the two? This would let you see if its a broken wire in the wiring harness.

So.. I checked the wiring, and went to local Honda dealer to get a wiring diagram, it all checks out. I connected a multi meter to the wires leading to the solenoid valve and drove around and found that it only gets the 12v signal after 3400 to 3800 rpm is this normal? I have installed a new egr valve, O2 sensor, and a new cat but I think I messed up by gutting out the catalytic converter that is right after the manifold can any one give some guidance

You sure did. The lean burn engines (D15Z1 & D16Y5) produce a high level of NOx. Honda found it necessary to place the cat converter directly on the exhaust manifold for these motors in order to heat the cat converter enough that it can bring down NOx.

I checked dealer for replacement $550 +++:eek: . i checked with local mufler shops and they cant even get the part to quote me a price. :confused: . any ideas??????

Maybe a junkyard "new arrival" would still have cat attached. Find the years/models that use the same cat and call around.

VX Catalytic Converter on Ebay
First time I've actually seen one for the VX!
96-00 Maniverter
^^^Could use that, IIRC it lines up with the stock VX B-pipe, but you would need to get an O2 bung plug for the lower O2 sensor hole, they're cheap and can be had at just about any exhaust shop.
One for $100 and free shipping (96+ style)

Hope that helps you out some.

Bought new catalytic converter, installed , had it tested fails again . I NEED HELP


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Sounds to me like the EGR passages are clogged in the intake.
Changing the converter won't help NOX.
You said the EGR wasn't working before, is it now?
What is the number on your ECU?
Has it ever passed as long as you have owned it? How many miles?
Please list all the numbers from the smog test.

He said the ECU isn't sending signal to the EGR. It would only do that if it was in limp mode or it was a bad ECU. Jumper the ECU diagnostic plug and put the key on. Count the flashes and compare it to repair manual.

How much would you be willing to pay for a VX cat converter that recently passed smog in CA and hasn't been used since?