Passed Smog... on the 3rd try
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Car: 1991 Camaro Z28
Engine: 5.7 TPI, Dyno Don Headers
Transmission: 700R4
Axle/Gears: Eaton Posi - 3.42
Passed Smog... on the 3rd try
If anyone is having issues with high NOX readings, lower your Main Spark Advance Table (filled mine with all 10s) and you can seriously reduce it. Spent hours chasing EGR issues and catalytic converter issues that weren't the problem... when all I had to do is burn a chip. Hopefully this saves you time.
1st Test
Failed... Modified Headers
HC 15mph 81(MAX)/65
HC 25mph 58(MAX)/44
CO% 15mph .50(MAX)/.13
CO% 25mph .40(MAX)/.09
NOX 15mph 537(MAX)/1279
NOX 25mph 494(MAX)/1179
2nd Test
Pass... Modified Headers (with sticker from SLP)
HC 15mph 81(MAX)/17
HC 25mph 58(MAX)/10
CO% 15mph .50(MAX)/.03
CO% 25mph .40(MAX)/.02
NOX 15mph 537(MAX)/1291
NOX 25mph 494(MAX)/1243
3rd Test
HC 15mph 81(MAX)/54
HC 25mph 58(MAX)/16
CO% 15mph .50(MAX)/.23
CO% 25mph .40(MAX)/.08
NOX 15mph 537(MAX)/433
NOX 25mph 494(MAX)/456
1st Test
Failed... Modified Headers
HC 15mph 81(MAX)/65
HC 25mph 58(MAX)/44
CO% 15mph .50(MAX)/.13
CO% 25mph .40(MAX)/.09
NOX 15mph 537(MAX)/1279
NOX 25mph 494(MAX)/1179
2nd Test
Pass... Modified Headers (with sticker from SLP)
HC 15mph 81(MAX)/17
HC 25mph 58(MAX)/10
CO% 15mph .50(MAX)/.03
CO% 25mph .40(MAX)/.02
NOX 15mph 537(MAX)/1291
NOX 25mph 494(MAX)/1243
3rd Test
HC 15mph 81(MAX)/54
HC 25mph 58(MAX)/16
CO% 15mph .50(MAX)/.23
CO% 25mph .40(MAX)/.08
NOX 15mph 537(MAX)/433
NOX 25mph 494(MAX)/456
Last edited by Marc Maro; 01-22-2013 at 01:18 PM. Reason: updated figures
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Car: 1987 IROC-Z
Engine: TPIS II Supercharged w/Nitrous
Transmission: 700R4 Probuilt
Axle/Gears: 3:73 Richmond 12 Bolt
Re: Passed Smog... on the 3rd try
Did you notice any performance gain? Probably not.. California emissions are the hardest to pass and cars have crazy parts that are totally different than Federally regulated cars. Good job on passing that test..
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Car: '91 Z28 L98 G92
Engine: Modded L98
Transmission: Modded 700R4
Axle/Gears: Modded 10-Bolt
Re: Passed Smog... on the 3rd try
" California emissions are the hardest to pass and cars have crazy parts that are totally different than Federally regulated cars."
What are some of these 'crazy' parts? I live in California, bought my Z28 in California, I pass emissions tests in California.
What are some of these 'crazy' parts? I live in California, bought my Z28 in California, I pass emissions tests in California.
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Car: 1987 IROC-Z
Engine: TPIS II Supercharged w/Nitrous
Transmission: 700R4 Probuilt
Axle/Gears: 3:73 Richmond 12 Bolt
Re: Passed Smog... on the 3rd try
I believe it starts with your ECM.. Maybe I am wrong, but CA emissions is different than any other state. Even when I worked in Autozone, I would have to ask if it is Federal Emisions or California Emissions on alot of cars. I would be interested in knowing what ECM and Prom you are using by number
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Car: 1987 GTA Vert & 1991 GTA 5 Speed
Engine: 87 GTA-L98 91 GTA LB9
Transmission: GTA-700R4 & GTA T5
Re: Passed Smog... on the 3rd try
Solved my high NOX by reducing the timing in the 1000-2000 RPM range in the main spark table. If you can burn a chip, it's pretty easy to do.
https://www.thirdgen.org/forums/tpi/...ml#post5477561
Thanks Marc. I have no idea how to burn a chip (have no chip burning equipment either). I need a remedy quickly. I guess I could have someone to burn a chip for me. Any other options on this? By the way how did your car run after that?
Last edited by Slowridr; 01-31-2013 at 06:14 AM.
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Car: 1987 GTA Vert & 1991 GTA 5 Speed
Engine: 87 GTA-L98 91 GTA LB9
Transmission: GTA-700R4 & GTA T5
Re: Passed Smog... on the 3rd try
This is good info. I haven't passed a CA emissions testing since '06.
In any case I found that my timing was set to 8 BTDC so I dialed it back a little to 6 BTDC and it passed. Try checking your timing and if that's the issue, dial it back some. I know that works for high NOX not sure if it works for anything else.
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Car: 1991 Camaro Z28
Engine: 5.7 TPI, Dyno Don Headers
Transmission: 700R4
Axle/Gears: Eaton Posi - 3.42
Re: Passed Smog... on the 3rd try
that should work, just don't try running with that table on the street. very little power.
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Re: Passed Smog... on the 3rd try
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Car: 67 ******mobile
Engine: 385 Solid roller
Transmission: T-56
Axle/Gears: 4.11
Re: Passed Smog... on the 3rd try
Far as I know all 50 state cars had the same emissions everything on them.
Ca just regulates its all there more than most
Ca just regulates its all there more than most
#13
Re: Passed Smog... on the 3rd try
You have not been driving your car since 06'?
In any case I found that my timing was set to 8 BTDC so I dialed it back a little to 6 BTDC and it passed. Try checking your timing and if that's the issue, dial it back some. I know that works for high NOX not sure if it works for anything else.
In any case I found that my timing was set to 8 BTDC so I dialed it back a little to 6 BTDC and it passed. Try checking your timing and if that's the issue, dial it back some. I know that works for high NOX not sure if it works for anything else.
88 gta 5.7 L98 auto
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Re: Passed Smog... on the 3rd try
hi, I had a question, I’m getting ready for a smog check in California and I’ve read many different tips including back off the timing a bit so I set mine back from 6 btdc to 8 btdc. From your experience this is opposite. I’m just trying to get any helpful info from other peoples trial and errors to help me if you have any input I’d appreciate it thank you!
88 gta 5.7 L98 auto
88 gta 5.7 L98 auto
Reducing ignition advance is one easy way to reduce cylinder pressure/temperature, but there's lots of others.
Adam
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