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CA Smog high NOX with 3800 by duckwalk39
Started on: 03-21-2014 05:49 PM
Replies: 14 (295 views)
Last post by: duckwalk39 on 03-23-2014 10:43 AM
duckwalk39
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Report this Post03-21-2014 05:49 PM Click Here to See the Profile for duckwalk39Click Here to Email duckwalk39Send a Private Message to duckwalk39Edit/Delete MessageReply w/QuoteDirect Link to This Post
Hi all,

So I'm failing my smog test in California with my 88 GT 5-spd with series 2 3800 L67.

The ONLY reading that is off is very High NOX at 15 MPH, 25 MPH NOX reading is very low.

What could be the cause of this?

Thanks!
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nosrac
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Report this Post03-21-2014 07:44 PM Click Here to See the Profile for nosracSend a Private Message to nosracEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by duckwalk39:

Hi all,

So I'm failing my smog test in California with my 88 GT 5-spd with series 2 3800 L67.

The ONLY reading that is off is very High NOX at 15 MPH, 25 MPH NOX reading is very low.

What could be the cause of this?

Thanks!


EGR not turning on @ 15 mph?

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fiero5150
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Report this Post03-21-2014 08:26 PM Click Here to See the Profile for fiero5150Send a Private Message to fiero5150Edit/Delete MessageReply w/QuoteDirect Link to This Post
Just had my 88 GT, V6 smogged this afternoon. The NOX readings at both 15 mph and 25 mph were super high and way above the max allowed. The technician found that the gas cap was not holding pressure as a result of cracked rubber o-ring on the cap. The second issue was that the timing was 24 degrees. It was way off where it should have been (10 degrees). He installed a new gas cap and reset the timing to 10 degrees and the 15 mph NOX reading went from a reading of 1062 to 137. The 25 mph reading dropped by half. It passed smog with flying colors. I realize you don't have the V6 and that your 25 mph reading was low. I don't know if this info will be of any value, but I thought I would share it with you just in case it may do some good. Good Luck.
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duckwalk39
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Report this Post03-21-2014 09:21 PM Click Here to See the Profile for duckwalk39Click Here to Email duckwalk39Send a Private Message to duckwalk39Edit/Delete MessageReply w/QuoteDirect Link to This Post
I guessed that the EGR might not be turning on at 15mph, but can't figure out why. What would cause that? Woud that really be the case? And how would I find out?
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duckwalk39
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Report this Post03-21-2014 09:22 PM Click Here to See the Profile for duckwalk39Click Here to Email duckwalk39Send a Private Message to duckwalk39Edit/Delete MessageReply w/QuoteDirect Link to This Post

duckwalk39

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quote
Originally posted by fiero5150:

Just had my 88 GT, V6 smogged this afternoon. The NOX readings at both 15 mph and 25 mph were super high and way above the max allowed. The technician found that the gas cap was not holding pressure as a result of cracked rubber o-ring on the cap. The second issue was that the timing was 24 degrees. It was way off where it should have been (10 degrees). He installed a new gas cap and reset the timing to 10 degrees and the 15 mph NOX reading went from a reading of 1062 to 137. The 25 mph reading dropped by half. It passed smog with flying colors. I realize you don't have the V6 and that your 25 mph reading was low. I don't know if this info will be of any value, but I thought I would share it with you just in case it may do some good. Good Luck.



Well the gas cap is new, and I;m not sure a timing issue would only effect it at low low speeds like 15 mph. I was hoping it was something that simple. Thank you though!
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donuteater306
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Report this Post03-22-2014 01:15 AM Click Here to See the Profile for donuteater306Click Here to Email donuteater306Send a Private Message to donuteater306Edit/Delete MessageReply w/QuoteDirect Link to This Post
I think I spoke with the owner of the shop that's working on your vehicle. Was kinda random, I saw a black Fiero and inquired about the repairs. If this is the same vehicle, he was talking about increasing the amount of EGR by playing with the different size washers that came with the valve. I'm assuming that didn't work?
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nosrac
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Report this Post03-22-2014 01:27 AM Click Here to See the Profile for nosracSend a Private Message to nosracEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by duckwalk39:

I guessed that the EGR might not be turning on at 15mph, but can't figure out why. What would cause that? Woud that really be the case? And how would I find out?

Faulty EGR, weak vacuum, PCM not in sync with vehicle speed/ TPS threshold?

A good article below:

http://www.autoshop101.com/forms/h61.pdf
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nosrac
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Report this Post03-22-2014 01:32 AM Click Here to See the Profile for nosracSend a Private Message to nosracEdit/Delete MessageReply w/QuoteDirect Link to This Post

nosrac

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quote
Originally posted by duckwalk39:

So I'm failing my smog test in California with my 88 GT 5-spd with series 2 3800 L67.

Thanks!


5 speed didn't come with the 3800? Cali certifies those vehicles now? Who programmed your PCM? The enabled threshold can be programmed.
Also, what do you have for a VSS solution?
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duckwalk39
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Report this Post03-22-2014 04:37 AM Click Here to See the Profile for duckwalk39Click Here to Email duckwalk39Send a Private Message to duckwalk39Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by donuteater306:

I think I spoke with the owner of the shop that's working on your vehicle. Was kinda random, I saw a black Fiero and inquired about the repairs. If this is the same vehicle, he was talking about increasing the amount of EGR by playing with the different size washers that came with the valve. I'm assuming that didn't work?


That's an interesting idea: Smaller washer sizes to increase vacuum pressure?. No that propbably wasn't my car, I have a dark blue one and it's not quite ready for the public yet. I only take it to a shop in South San Francisco where I had a smog guy. Rumor has it he's not in that kinda business anymore so now I'm stuck trying to figure out this problem I've had since 2008.

Again, that's an interesting thought, didn't know it was possible
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duckwalk39
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Report this Post03-22-2014 04:41 AM Click Here to See the Profile for duckwalk39Click Here to Email duckwalk39Send a Private Message to duckwalk39Edit/Delete MessageReply w/QuoteDirect Link to This Post

duckwalk39

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quote
Originally posted by nosrac:


5 speed didn't come with the 3800? Cali certifies those vehicles now? Who programmed your PCM? The enabled threshold can be programmed.
Also, what do you have for a VSS solution?


Correct, the 3800 never came with a 5 spd, but the BAR ref didn't seem to eith care or notice. I got a sticker for the car and I was pretty surprised. I can't even remember who reprogrammed the computer it was such a long time ago, I'm going to need to look at the ol build binder for all the info.
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iluvsd619
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Report this Post03-22-2014 12:15 PM Click Here to See the Profile for iluvsd619Click Here to Email iluvsd619Send a Private Message to iluvsd619Edit/Delete MessageReply w/QuoteDirect Link to This Post
the 3800 n/a came out with a 5 speed in the 1998 Camaro
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iluvsd619
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Report this Post03-22-2014 12:18 PM Click Here to See the Profile for iluvsd619Click Here to Email iluvsd619Send a Private Message to iluvsd619Edit/Delete MessageReply w/QuoteDirect Link to This Post

iluvsd619

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I need to go to your ref. lol!
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duckwalk39
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Report this Post03-22-2014 08:03 PM Click Here to See the Profile for duckwalk39Click Here to Email duckwalk39Send a Private Message to duckwalk39Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by iluvsd619:

the 3800 n/a came out with a 5 speed in the 1998 Camaro


Yeah that was my mistake. The supercharged series II never came with a manual.
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donuteater306
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Report this Post03-23-2014 02:14 AM Click Here to See the Profile for donuteater306Click Here to Email donuteater306Send a Private Message to donuteater306Edit/Delete MessageReply w/QuoteDirect Link to This Post
What shop in South City do you take it to? I'm looking for a reputable place now that my friend's shop has changed hands.
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duckwalk39
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Report this Post03-23-2014 10:43 AM Click Here to See the Profile for duckwalk39Click Here to Email duckwalk39Send a Private Message to duckwalk39Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by donuteater306:

What shop in South City do you take it to? I'm looking for a reputable place now that my friend's shop has changed hands.


The best shop I've taken it to thus far was to Ditos Motors in SSF. They are a bit expensive but they do custom dyno tuning (a shop built for performance work) and are honest in what they can do for you. For more generic repairs that are a bit out of your skill range or requires equipment that you may not have, try Miller & O'Brian in Pacifica. I've taken all my vehicles there when the skill level for some repairs were just too much.
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