Help!

 

Isn't that the EGR?

 

No. That's the vacuum fitting for the secondary intake butterflies.
Neither the second or third-gen Integras use EGR. But you do need to replace the PCV valve in the course of a tune-up.
I do mine with every set of spark plugs (30K).

 

Ahhh. That makes sense. It's my buddies car, keeps failing emissions. Changed the cat, o2 sensor, plugs, wires, pcv valve, and put on an AFPR, but it keeps failing.
Not sure what else to do.

Any ideas?

---------- Post added at 02:03 PM ---------- Previous post was at 01:59 PM ----------

Is that the IAB (Intake Air Bypass)?

 

Since you've asked about EGR, I take it the car fails because of high NOx.
First guess is it's running lean and that the aftermarket FPR is to blame.

If you've got the stock FPR, and its working, I would switch back to it for the re-test.
Belt-and-suspenders, put the OEM intake back on as well.

 

It first failed HCO and NOX. We didn't know it didn't have a cat.
Put a new cat on, it passed everything but NOX.
So we got the AFPR and turned the fuel pressure up a bit, it then failed HCO and NOX again, but even worse than the original time.
Turned the fuel pressure down quite a bit, and it failed NOX.

It's getting quite frustrating.

 

Yes, but don't let the name mislead you.
All that vacuum hose is doing is drawing against a solenoid valve.
Once that valve is opened, engine vacuum is used (via a diaphragm) to open the butterfly valves and give the intake charge a shorter path.

It's possible you've got a vacuum leak in either the feed hose, or the IAB check valve, but my money is on the aftermarket FPR as the source of your problems.

It's probably got some carbon build up, and that plus a hot engine will bump the HC output.
Rather than blindly chase a correct air:fuel ratio with a questionable FPR, I'd just bite the bullet and replace it with an OEM unit.

 

What about retarding the timing just for the test? You should get lower NOX emissions (along with less power)