So I just got my wife a 98 Civic Hx D16y5 SOHC auto VTEC-e engine. And the car would not pass emissions.The (CEL) was on. So I went to autozone and had them pull the codes, P0401 Insufficient flow, probable cause faulty EGR valve, blocked EGR passage ways in engine? So I kept read about the blockage. I about **** when I found this.

http://www.tegger.com/hondafaq/egr-fix/index.html
Theses two Guys rock.

Piror to finding this I changed the EGR valve EGR solenoid, O2 senors.
New wires and plugs, I also changed all the seats and Orings on the injectors.

So I started taking out all the crap that was in the way. and low and behold I found the blockage.

All 4 holes are plugged.


Insufficient flow huh try no flow.






I cleaned everything up like tegger showed.
I should have went and got a new gasket, but no. Now that I have done it, I can do it again. So I put it all back together. I reconnected the battery, and it starts right up. It already runs and sounds better.
So I jump in and go for a nice drive. I did stop and turn the car a few times, just to see if the (CEL) would come back on. And the light did not come back on.
At this point I went back to autozone, and got no bad codes this time.

So first thing in the morning I went though Emissions, and it passed. I can now put the car in my name.
The car runs way better, but I still have a low idle. I did some reading on low idle, and changing the map senor or the tps might fix this?
Not sure what to do next ?
So if anyone has any suggestions to point me in the right direction , that would be great.

Thanks David

 

First off is the idle really low? If the engine runs without shaking, the idle is OK; don't trust the dash tach to be that precise.

If it really is low the first thing to do is take off the IACV and clean it, also of course clean the passages feeding it. I think on your HX auto the IACV will be on the bottom of the throttle body rather than on the back as it is for manuals.

 

Thanks for the reply, The car does not have a low idle all the time, just when it's in gear, like at a stop light. the car run fine tell that point. when I stop the idle goes from 950 rpms to about 250 rpms, it does'nt die though. So i gonna go ahead and clean the IVAC and see if that helps.

Again Thanks for the reply.

 

Ok so I have been looking for the IACV, I dont have a book, so i have been going by what I have read, And this the only thing i find on or around the manifold.

Could someone tell me if i right?

 

That is it. Was the plug (on the left side of the picture) always unplugged? Clearly it's not going to work that way.

 

lol... no I unplugged it. anyways I took it off. Surprisingly enough it was not clogged at all. Cleaned it up anyway, and put it all back together. it didn't really change the way the car ran. The idle would go low at a stop light. I did unplugged it while the car was running , and the idle shot way up. plugged it back in a it came back down. That tells me it's working right? So i turned the idle up a little and it seems to be ok. it doesn't surge like it did.