After failing my smog check on my 01 civic dx w/ 143k mi, i looked over the form and saw that i failed for dirty emissions for NOx, and the other areas passed but were kinda high. The HC measured 27-28 , CO were .18-.17. BUT, i also FAILED the ECS Air Injection test. I looked all over the engine without removing anything for how the emission system is set up on this car without figuring out much other than the cat is attached to the header with an O2 sensor before n after the cat. Ive been trying to find info on this problem and i guess a lot of cars have what is called a "smog pump". I have no idea if this car has one or if it even recycles air back into the exhaust.
Also a few things I've noticed while driving the car is that on most start ups(as well as randoms times on the road, mostly when i come to stop and am idling) ill hear a squeals whirring whine that sounds like bad belt, but I know its not the belts cause i changed em all at 120k mi, and have since tensioned multiple times to try to stop the squeal. I can usually give the engine a little rev and the squeal will cease, but intermitently start up again. when the engines warm i have to give it a pretty hard rev to cut the sound temporarily again.
On the road when i intentionally bog the engine or like go up a hill at ~25mph in 4th or 5th gear and floor the gas, i hear a similiar squeal to the other sound i usually hear after starting(except it is not a nonstop squeal, but rather right a sqealing machine gun sputtering).
Any advice, diagrams, pictures, etc that could help me fix this problem would be greatly appreciated.

 

I've been doing some research and it seems that i might have a problem involving an engine vacuum leak and/or an EGR valve issue. I have not been able to find any diagrams showing the location of the EGR valve and ive looked around the engine bay a bunch with no luck. Any one know how to find a leak in the vacuum as well as locate the egr valve?

 

First thing to do is scan it for codes (most auto parts stores will do it for free).

Secondly- yes, a bad EGR (or clogged EGR passages) can cause high NoX. You can always pull the EGR and clean it and the passages (brake or carb cleaner). Also, push the piston in the EGR to see if it moves freely.

The EGR is the thing with the sticker:

It's right between the valve cover and giant airbox on the passenger side of the engine bay.

To check for vacuum leaks: spray carb cleaner around the vacuum hoses and around the gaskets (throttlebody, intake, valve cover, etc.) a little at a time and listen for the idle to raise when you spray it on a particular section.

*DO NOT spray anything on the exhaust*

 

thanks for the picture and advice, both are very helpful. As far as codes go, I did get a P0420(cat inefficiency), but only once and that was after the car was sitting for 2 months. I have been having an intermittent problem though, mostly on hot days, my engine will randomly go into limp mode until things cool down a bit. It registers codes P1361 and P1362, something about TDC sensor. im not so sure this problem and the egr valve are related though.

 

DIY diagnosis of OBDII codes P1361 or P1362

1. With the ignition OFF, disconnect the sensor (it's at the end of the screwdriver):


2. Turn the ignition to ON(II). Not running, just the accessory position.

3. Measure for battery voltage (12-14V) from the yellow/black wire on the connector to body ground.

Did you get battery voltage?

YES- Step 4

NO- Repair open in the wire between the PGM-FI main relay (behind the glovebox) and the sensor.

4. Measure voltage between the green wire and body ground

Is there about 5V?

YES- step 5

NO- step 7

5. Still at the connector, measure voltage between the yellow/black wire and brown/yellow wire.

Is there voltage?

YES- step 6

NO- Repair open in the wire between the sensor and G101 (the ground running from the engine to the radiator support).

6. Replace the sensor with a known good one. Then re-set the ECM/PCM?

Is it still throwing codes P1361 or P1362?

YES- Update or replace the ECM/PCM

NO- problem solved

7. With the connector still plugged in (the multi-meter probe should be sharp enough to pierce the insulation on the wire), measure voltage from ECM/PCM connector A26 (green wire) to body ground.

Looking at it still in the dash, it's the bottom connector (It's also the only 31 pin connector and, you can actually see the wire I'm talking about in the bottom of the pic):


Is there about 5V?

YES- Repair open in the wire between ECM/PCM A26 and the sensor

NO- step 8

8. Turn the ignition OFF and disconnect ECM/PCM connector A.

9. Check for continuity (Ohms) between ECM/PCM connector A26 and body ground.

Is there continuity?

YES- Repair open in the wire between ECM/PCM connector A26 and the sensor

NO- Update or replace the ECM/PCM

* The usual places to find a bad wire is at the connector and the firewall. If I don't find anything at those places I usually just run a new wire.

*Also, start by inspecting ground wire G101 (engine to radiator support) and repairing or replacing it if necessary.

 

Thanks, this is really helpful. I ordered a new cam position sensor so im hoping it will be the fix, but if not ill continue these steps. Oh and BTW i learned found out that the 01-03 DX/LX does not have a EGR valve. I have been also getting code P0420 lately so I think my cat may actually be bad too. I live in CA and everywhere I've looked online won't ship a cat here. On this car the cat is connected to the exhaust manifold. I think the dealer charges roughly 900 for this part. If I brought it to a local mechanic, can he order an aftermarket cat, or am I stuck paying 900??

 

Can't pass smog with an aftermarket cat in Cali. You can only use OEM.

Get one much cheaper here (number 4): http://www.hondapartscheap.com/south...t=0&quantity=0 and have the local mech put it on for ya. Should run $100-150 for labor.

You're also gonna need numbers 15, 16, and 17.