Partizan

I took my car to get it smogged today, and it surprisingly failed. The car passed everything but the NO(PPM) test, where I got 1080 and the max allowed is 487. This was at 15 mph, while at 25 mph the car passed, got 362 out of 774.

Now, my car is a 96 ej8 with the stock motor, except for aem sri, edelbrock header, and apexi ws2 exhaust.

I have to register this car in a couple of days and need to pass soon. Any ideas on what could be the problem? Cat?

roycivic92

i think your car is running lean, i think my car was doing that. when my car got stolen i put in a dx ecu and mine is a y8 motor.

SGVridgerunner

It's true, you're running lean. Check your fuel pressure.

I notice you have a header, I don't know about anyone else, but I've never been able to pass smog with a header on, even if it's CARB legal. Try throwing a stock ex. manifold on and see.

roycivic92

x2

Partizan

Do you think that the intake could also be causing this problem?

roycivic92

maybe . get a fuel pressure regulator.

Partizan

How do I check the fuel pressure?

Partizan

Here is my sheet. Anyone know why I fail at 15 mph so badly for the nox and not at 25?

egwhte

interesting.

SGVridgerunner

No, the intake won't have anything to do with it because the MAP sensor compensates fuel for the reduced pressure loss through the intake. What could be holding you up is if your fuel filter is slightly plugged or if you have a bad FPR. You can check your fuel pressure with a gauge from B&M ($35).

Also, with the headers, if they relocate the O2 sensor further down the exhaust stream, it will read wrong. Your cheapest solution is to try swapping your stock manifold back on and retest.

roycivic92

yeah nox is when its running lean. make your car stock again and change your fuel filter

Partizan

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SGVridgerunner &raquo;</TD></TR><TR><TD CLASS="quote">No, the intake won't have anything to do with it because the MAP sensor compensates fuel for the reduced pressure loss through the intake. What could be holding you up is if your fuel filter is slightly plugged or if you have a bad FPR. You can check your fuel pressure with a gauge from B&M ($35).

Also, with the headers, if they relocate the O2 sensor further down the exhaust stream, it will read wrong. Your cheapest solution is to try swapping your stock manifold back on and retest. </TD></TR></TABLE>

Any other ways to check fuel pressure(ie something from autozone, etc?)

The edelbrock header does in fact locate the 02 sensor right next to the catalytic converter, you really think that would make the readings different?

Partizan

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by roycivic92 &raquo;</TD></TR><TR><TD CLASS="quote">yeah nox is when its running lean. make your car stock again and change your fuel filter</TD></TR></TABLE>

You think i should put the intake, exhaust, and header back to stock? Why would the exhaust matter for the readings?

SGVridgerunner

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Partizan &raquo;</TD></TR><TR><TD CLASS="quote">

Any other ways to check fuel pressure(ie something from autozone, etc?)

The edelbrock header does in fact locate the 02 sensor right next to the catalytic converter, you really think that would make the readings different?</TD></TR></TABLE>

Yes, change your header and you should be fine.

Example, mine: CAI, cam, VAFC, DC4-1, full exhaust - Fail
Everything, but with stock EM instead of DC4-1 - pass, barely.

I know, it confused me for the longest time. I tried everything to go around it, but it all comes down to O2 location.

meandino

Hey try some sea-foam in your gas tank first and try to pass it like that. That stuff is guaranteed to pass. GL

Partizan

just wondering, when you went to smog your car, did it have high nox with the aftermarket exhaust manifold like mine is?
Did it pass for 25 mph with aftermarket?