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Old 04-30-2008, 07:26 PM   #1
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Default Failed smog today.. What should i do guys?

Before i dove into the forced inducted world i figured ide get my car smoged since i had another 4 week to complete it. I put the stock AFM, ecu and air filter all back on. Figured ide by just fine, however that is not the case.

During the 15 and 25 mph driving on the machine my No(PPM) numbers were a bit too high. The average at 15 mph is 237 and the max is 847 while my 90 did 989 and at 25 mph the average is 199 max is 786 while my numbers were at a high of 953.

The tech said it was most likely my cat causing the high numbers and stated that on a personal level i should possibly retard the timing, get a new cat and run 91 fuel.

It has stock header/cat (original 106k miles) and a magnaflow muffler. The timing is advanced to 14 degrees while on the stock ecu.

For those of you who have failed smog what have you done to fix it?
Thanks all
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Old 04-30-2008, 07:30 PM   #2
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too lean, too advanced.
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Old 04-30-2008, 07:34 PM   #3
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I was thinking of throwing the megasquirt back in and tuning it a bit richer in the "15 mph and 25 mph" zones and giving it another shot. What is your guy's suggestion on my timing map, throw it all into 10 degrees just to be safe?
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Old 04-30-2008, 07:55 PM   #4
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set the timing back to 10 and try again on the stock ecu, if it still no good you may need a new cat
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Old 04-30-2008, 08:10 PM   #5
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Did you make sure the CAT was hot and didn't cool down before test... i know that it will help an older unit to work better.
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Old 04-30-2008, 08:30 PM   #6
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retard timing and it should clean it up some.

if all else fails move to another state.
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Old 04-30-2008, 08:33 PM   #7
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Brainey's right. All else being equal, high NOx is a byproduct of increased in-cylinder temp / pressure, which can be indicative of a lean mixture or overly advanced timing. Since we know your timing is too advanced, dial it back to maybe 8 degrees BTDC at warm idle with the TEN-GND jumper. 91 octane will also slow the burn a little and should help NOx as well.

What were your HC and CO numbers? Those will give us an indication as to how the mixture is running.

Some helpful info: http://www.firstfives.org/faq/smog/smog_faq.html
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Old 04-30-2008, 09:29 PM   #8
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My hc numbers were as follows:
15 mph was @ 63 w/ a max of 134 and average of 31
25 mph was @ 56 w/ a max of 108 and an average of 20

CO numbers were as follows:
15 mph was @ .17 with a max of .82 and an average of .1
25 mph was @ .19 with a max of .71 and an average of .09

Ill manually retard the timing to 8* BTDC and go in for a re test tomorrow afternoon, thanks all

Edit: Cat was hot, well it idled for about 3 min before getting put to the test after a 10 min drive to the local test only station.

Last edited by thesnowboarder; 04-30-2008 at 09:40 PM.
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Old 05-01-2008, 10:30 PM   #9
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Damn, i'm soooooo happy i live in FL...
Hope u pass on the next one
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Old 05-02-2008, 02:31 AM   #10
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Hmmmm. Based on the HC numbers you're not running ultra-lean, so I'm thinking it's either the timing, or the cat is on its way out.

Retarding the timing should help, a tankful of 91/93 octane fuel might also add a slight edge.
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Old 05-02-2008, 03:09 AM   #11
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Quote:
Originally Posted by Joe Perez View Post
Hmmmm. Based on the HC numbers you're not running ultra-lean, so I'm thinking it's either the timing, or the cat is on its way out.

Retarding the timing should help, a tankful of 91/93 octane fuel might also add a slight edge.
Im going to retard it back to 10* tomorrow and hope that works, i use CA's best pump gas all the time, lame 91

Edit: Post number 420 w00t
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Old 07-26-2008, 11:02 AM   #12
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Quote:
Originally Posted by thesnowboarder View Post
Im going to retard it back to 10* tomorrow and hope that works, i use CA's best pump gas all the time, lame 91

Edit: Post number 420 w00t
How did you do?
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