uh-oh, failed emissions test

autoxer7 · 05-28-2004, 07:48 PM

I just failed the WA state emissions test with my VE. Here is the pertinent data:

Cruise Limit HC (ppm): 160
Cruise Emissions HC: 214
Cruise Result HC: FAIL

Cruise Limit CO%: 1.2
Cruise Emissions CO%: 0.77
Cruise Result CO%: PASS

Idle Limit HC (ppm): 220
Idle Emissions HC: 213
Idle Result HC: PASS... barely!

Idle Limit CO%: 1.2
Idle Emissions CO%: 0.18
Idle Result CO%: PASS

The cruise part of the test is done on a dyno. In my case this was 2nd gear at about 25 mph or 2000 rpms.

According to the handout they give you when you fail "... a very lean air/fuel mixture can cause HC failures." I'm running with an adjustable FPR at 28 psi at idle (stock on a DE is 36 psi). I'm thinking all I need to do is tune my FPR for 36 psi and retake the test. Thoughts?

Edit: I think a very lean air/fuel mixture would be a problem if I'm getting a misfire at idle... I'm quite certain this isn't the case. I was thinking instead of doing the Jay Hass trick of dumping a gallon on denatured alcohol in a 1/4 tank of gas would do the trick?

Thanks,

Steve

Harris · 05-28-2004, 08:11 PM

Could be a bad cat too. Your CO emmissions weren't too far from the limit.

autoxer7 · 05-28-2004, 08:35 PM

Quote:

Originally Posted by Harris

Could be a bad cat too. Your CO emmissions weren't too far from the limit.

Thanks. Yeah, I was thinking that, too. I have an aftermarket cat (Random Tech) that is about six years old.

autoxer7 · 05-28-2004, 09:30 PM

Here is a fairly simple explanation of what to expect with ignition timing and fuel mixture changes: Aussie emissions tuning

I'm gonna try retarding the timing by about 7 degrees and lean the fuel mixture just a couple more psi.

Steve

98sr20ve · 05-28-2004, 10:26 PM

My guess is at that fuel pressure you are running really lean. Oh, well your engine not mine

92nx2k · 05-29-2004, 08:06 PM

yeah mine is at 50 psi with stock reg. 28 is lean probly.

JustinP10 · 05-29-2004, 09:55 PM

you could put a restrictor plate right behind the cat (where the gasket sits) to help keep the cat hot too?

VVLtrain · 05-31-2004, 10:51 AM

Quote:

Originally Posted by JustinP10

you could put a restrictor plate right behind the cat (where the gasket sits) to help keep the cat hot too?

I believe when you do that, the CO% shoots up. I may be wrong, but IIRC that has worked for some people with luck but the same "can't have your cake and eat it too" applies here. I'd say give it a shot. But it may flip flop your levels.

-Linus

La_Noche · 05-31-2004, 01:50 PM

hmm i failed for emmisions. bad cat and exhaust system leaks.

xt_out · 06-03-2004, 05:14 AM

my SER just failed WA state emissions too. my hydroCarbon number was 2000+
it gets 160 miles on a tank of gas and was getting a CEL for cylinder #1 misifre after plugs, wires, cap, rotor and knock sensor were replaced. 02 sensor might fix my problem but either way i've spent enough $$ to just get the damn waiver

guess thats what happens with a $1500 car. good luck to a fellow emission failer.
where in WA you at?

autoxer7 · 06-06-2004, 06:14 AM

Good news... I finally passed on the 3rd attempt.

2nd test (retarded the timing 10 degrees to 5 deg BTDC):

Cruise Limit HC (ppm): 160
Cruise Emissions HC: 202
Cruise Result HC: FAIL

Cruise Limit CO%: 1.2
Cruise Emissions CO%: 0.79
Cruise Result CO%: PASS

Idle Limit HC (ppm): 220
Idle Emissions HC: 96
Idle Result HC: PASS

Idle Limit CO%: 1.2
Idle Emissions CO%: 0.03
Idle Result CO%: PASS

3rd test (installed new CATCO cat replacing 6-7 yr old Random Tech, timing 5 deg BTDC):

Cruise Limit HC (ppm): 160
Cruise Emissions HC: 98
Cruise Result HC: PASS!

Cruise Limit CO%: 1.2
Cruise Emissions CO%: 0.16
Cruise Result CO%: PASS

Idle Limit HC (ppm): 220
Idle Emissions HC: 38
Idle Result HC: PASS

Idle Limit CO%: 1.2
Idle Emissions CO%: 0.01
Idle Result CO%: PASS

Retarding the timing improved idle HC emissions by more than 50%, and a new cat improved cruise HC emissions by 50% and idle HC emissions by a further 60%. I bought the direct fit CATCO cat complete with flanges from Summit Racing, part no CTO-4087, $112.94 delivered. The same "4087" cat can be ordered from here for $93.68 delivered, but I needed it before this weekend which is why I ordered mine from Summit (in stock, two days via UPS Ground). Even though the CATCO is advertised for a 240SX it had the exact same dimensions as my old Random Tech.

Steve

VVLtrain · 06-06-2004, 12:16 PM

Cool. Just out of curiosity, does Washington state have only an idle test or do they do a rolling test for emissions too?

-Linus

BlkB14 · 06-07-2004, 02:27 AM

Quote:

Originally Posted by Ltrain

Cool. Just out of curiosity, does Washington state have only an idle test or do they do a rolling test for emissions too?

-Linus

The cruise part of the test is done on a dyno. In my case this was 2nd gear at about 25 mph or 2000 rpms.

i think this would count as a rolling test. Cool thing about livin in Kitsap county Steve. we dont need to do emission testing

i have plenty of friends that roll around w/ no cats. not that i would do such a thing