88 GTU failed emissions
 

Here's my read out from 2 years ago:
15 mph:
RPM - 1817
%CO2 - 14.4
%O2 - 0.45
HC - 58 (118 max)
CO - 0.28 (0.75 max)
NO - 169 (799 max)

25 mph:
RPM - 1973
%CO2 - 14.39
%O2 - 0.48
HC - 62 (93 max)
CO - 0.30 (0.63 max)
NO - 193 (738 max)

Here's todays:
15 mph:
RPM - 1803
%CO2 - 14.2
%O2 - 1.0
HC - 91 (118 max)
CO - 0.49 (0.75 max)
NO - 94 (799 max)

25 mph:
RPM - 2041
%CO2 - 14.3
%O2 - 0.8
HC - 100 (93 max) FAILED
CO - 0.35 (0.63 max)
NO - 70 (738 max)

So the things that changed from 2 years ago....

Then:
Exhaust leak on edge of main cat
Pulling coolant into chambers
Pushing exhaust into coolant

Now:
Gutted pre-cats
Same main cat with leak on crimped edge
Freshly rebuilt motor with no leaks

Do you think it was the gutted pre-cats? I gutted them because the honeycomb melted and clogged them up. The main cat seems to have come uncrimped or something on an edge, so it leaks. Also the pre-cats have a hole in the bottom of each one?? It looks like a manufactured punched hole about 1/4" diameter.

Ideas?

Oh, it's also got a large streetport from the Pineapple template.

Gonna go test the O2 sensor with a multimeter on the green plug. If the O2 sensor is bad, that could be it.

This really sucks.

Well, O2 sensor is alternating what appears to be normally. It's only got about 10k miles on it anyways.

I took the main cat off and welded up the seam that was leaking.

I'm still getting a fffft ffffft sound from the cat at idle after warmed up.

I think it would be safe to guess the cat situation may have an effect on the change. Also the holes around the pipe may have been made by doing back pressure tests to find clogged cats and the plugs fell out

since HC, CO and NOx are all still low, but HC and CO went up, but NOx went down, it might be a little lean.

it still could be the o2 sensor. you may try playing with the AFM, or buy an SAFC or something too.

actually since NOX is so low, maybe advancing the timing would work, NOX WILL go up, but maybe the other two will go down enough, if you had a free retest i'd try that, if not SAFC

How are they allowing you to test with an exhaust leak?
Around here if you have any exhaust leaks they say Bye bye/Fix it.

Safe assumption. It was like a bulb went on in my head when I remembered that after the fact. In the past, I remember reading that the main cat should be sufficient.

I'll see about a free re-test. I'll try advancing the timing a little. I'm trying to avoid dropping another $150+ (SAFC or new cat) on this thing right now; I got bills and crap due.

The dude was cool. He said, "If it passes the sniffer, more power to ya!"



I've been told that I need more miles on the rebuild (it's got about 30 miles on it now) and the HC will come down. Also, how would running 91 octane instead of 87 octane (currently 1/4 tank of 87) affect it? I also realized this morning that my air filter was still on the workbench and not in the car. Geez, how many different ways can I screw up this test?? lmao


Thanks for your input, guys!

so happy that NY killed the roller/sniffer test. so many ways to get around it , just a waste of time

slower burn?

Right. I've read (google) that older cars pass smog easier with premium fuel instead of regular. Is it along the same lines as the ethyl alcohol in the tank, raising the octane?

octane has nothing to do with flame speed....

advancing the timing does get the combustion process started earlier, which SHOULD offer a more complete burn, which SHOULD lower HC and CO. NOX will go up about 200 for every 5 degrees of timing, but you have tons of room there, so it should be fine.

and actually you're so close you might just be able to get it hotter and pass

Do you think I should run premium for the re-test? I'll advance the timing a little bit.

if u are getting a re-test for free I don't see why not.

Turns out my TPS was horribly off (low). I adjusted it back up to ~1k ohm when hot at idle. I also advanced the ignition a tiny bit. It runs/idles sooo much smoother and stronger now!

Gonna have it re-sniffed tomorrow with premium (91) fuel.

good luck! the TPS runs the air control valve, so can make a big difference

Failed again.

CEL does not come on when the key is turned on.

It's not supposed to, it's an 88! Well, when I swapped in the dash from an S5, I musta put the S5 light cluster in as well, that would explain the fuel light coming on when the parking brake is set. Won't pass it despite documentation because the lens-icon-thingy is there "so it's supposed to light up".

The circuitry does not exist for it to light up!

Can't find my S4 light cluster.

FML.

Time for the black Sharpie marker mod!

Huge thanks to ROTARY POWERED for an S4 idiot light cluster!

So....IAT....I hate you.

Found that it was disconnected, but car was running great. Once reconnected it ran like poo. It even died on the smog dyno and had to push the car out. It would NOT idle once warm.

Needless to say, I failed.

Managed to get it home, pulled the plug off the sensor, resistance seemed normal (~5k ohm). Left it unplugged, car improved. This is after fixing the TPS and advancing the CAS a little. I also had 91 in it. My HC's were in the 120's at both 15mph and 25mph.

Gonna go back today or tomorrow without the IAT (as I ran it originally) and with 87 (as I ran it originally) and see how it does then (after the TPS/CAS adjustment). It should pass just fine!

I'm thinking I need to reconnect the IAT at some point and adjust the CAS with a timing light. I just need a timing light. I'll bug someone local this weekend.

if you want the sensor to look plugged in, put some black tape on one of the pins. you could bend the pin out of the way as well, but they are fragile.

So I grabbed an adjustable timing light from Harbor Freight.

I've got:
TPS set at 1k ohm at warm idle (was 400 ohm after first test)
CAS at 10 deg advanced (was 0 deg for first test)
IAT disconnected/hidden (same as first test)
1/4 tank of 87 octane (same as first test)
New air filter (same as first test)

It runs AWESOME! Hoping hoping hoping it passes tomorrow.

FUCK!!!!

5/3/12:
15 mph:
RPM - 1803
%CO2 - 14.2
%O2 - 1.0
HC - 91 (118 max)
CO - 0.49 (0.75 max)
NO - 94 (799 max)

25 mph:
RPM - 2041
%CO2 - 14.3
%O2 - 0.8
HC - 100 (93 max) FAILED
CO - 0.35 (0.63 max)
NO - 70 (738 max)

5/9/12:
15 mph:
RPM - 1835
%CO2 - 14.3
%O2 - 0.6
HC - 149 (118 max) FAILED
CO - 0.27 (0.75 max)
NO - 145 (799 max)

25 mph:
RPM - 2047
%CO2 - 14.5
%O2 - 0.2
HC - 163 (93 max) FAILED
CO - 0.39 (0.63 max)
NO - 86 (738 max)

Today 5/11/12:
15 mph:
RPM - 1827
%CO2 - 14.2
%O2 - 0.7
HC - 61 (118 max)
CO - 0.35 (0.75 max)
NO - 94 (799 max)

25 mph:
RPM - 2049
%CO2 - 14.2
%O2 - 0.7
HC - 140 (93 max) FAILED
CO - 0.27 (0.63 max)
NO - 99 (738 max)

Differences between first (5/3) and last (5/11)...reset TPS from 400ohm to 1kohm and advanced the timing by 10 degrees.

Why did my HC's go UP?!

Do I just need a new damned cat??

Would that little variable resistor have an effect? Everything I can find indicates this is a lean condition, but all my vacuum lines are brand new, injectors are freshly cleaned. The variable resistor is turned all the way left (lean?).

Another $35, and the shop is closed this weekend. I'll find another one.

This is a FRESH rebuild, everything new. It shouldn't be doing this. It passed emissions with 4 coolant leaks before it locked up on me.

Why is your variable resister set to full lean?

Also I feel bad for you guys who need to smog, I just my fc inspected and it has no cats.

I dunno. I never touched it. I'm out of ideas, so I checked it.

Gonna take it to a different smog shop today. That guy yesterday went from 15 to 25 in 2nd, then missed 3rd and almost jumped the car off the rollers.