Emmissions help

chuck88 · 11-29-2002, 10:30 AM

My 88GT just failed emissions.

HC 258 should be 180
CO 7.07 should be 1.01

Mods:
GT40 upper Lower (Ported & polished)
Pulleys
Headers
Dynomax
Cold air intake
Larger Throttle body (forgot size)
She passed last year with the same mods.

The car sits a lot could this have caused poor emssions? I have never changed the 02 sensors could this be my problem?

I don't know much about emissions is the car in trouble?

Please help (getting nervous)

Chuck88GT

sn95gt19 · 11-29-2002, 10:46 AM

i would change your o2's like you said, thats usually the reason that a car that previously passed fails! your numbers are looking a little steep to just be the o2's though. try the o2's and go from there. this might sound like a stupid question but you do have the cats still on the car right?

chuck88 · 11-29-2002, 10:56 AM

Yes I still have the stock cats are on.

Chuck88GT

PKRWUD · 11-29-2002, 04:41 PM

Did they also list the results for CO2 and O2? I can better tell you what's up when I have the results from a 4 gas analyzer.

How warm was the engine when you had it tested, and is your smog pump still in place?

chuck88 · 11-30-2002, 09:05 AM

Smog pump is still in place. I drove the car for about a 1/2 hr temp guage read 180.

NOx 0091 Standard =1378
HC 0258 Standard =0180
CO% 07.07 Standard =01.01
CO2% 08080 Standard =No #s
O2% 03.80 Standard =No#s
RPM 2420 Standard =No#s

Due to my newborn son the car has been neglected and the gas may have been 2 months old will this effect emissions?

Chuck88GT

PKRWUD · 11-30-2002, 03:08 PM

Okay. I'm presuming that the CO2 percentage was 8.8%. If that's the case, I think you may be okay. Your results indicate an extremely rich condition at first, but when you add the CO2 and CO percentages, you come up with better than 15%, which is equal to an air/fuel mixture of about 14.2, which is excellent.

Your CO2 is the result of the cat burning up the HC and CO. The higher the CO2, the better. Above 13% would be best.

So, the results tell me that your engine is fine, but the cat system that is supposed to convert the HC and CO isn't doing it's job. However, the CO is greater than the O2, which usually means the cats are okay.

Your main problem was that you didn't get the cats hot enough. You should be running a 192 t-stat, and getting the engine as hot as you can, without boil-over, just prior to the test. I like to recommend taking at least 30 minutes to drive to the shop, and keep it a gear lower than normal. Get that puppy HOT! Your cats are probably good for another year or two, but replacing them now would have a big effect.

Take care,
~Chris

11-29-2002, 10:30 AM	#1
chuck88 Registered Member Join Date: May 1999 Location: Wood Ridge NJ USA Posts: 341	Emmissions help My 88GT just failed emissions. HC 258 should be 180 CO 7.07 should be 1.01 Mods: GT40 upper Lower (Ported & polished) Pulleys Headers Dynomax Cold air intake Larger Throttle body (forgot size) She passed last year with the same mods. The car sits a lot could this have caused poor emssions? I have never changed the 02 sensors could this be my problem? I don't know much about emissions is the car in trouble? Please help (getting nervous) Chuck88GT __________________ So what if its "midlife crisis". Wife, 2 kids, busy job, "fixer upper" house, and I still have time for the Mustang!!! I Love my kids!!!

11-29-2002, 10:46 AM	#2
sn95gt19 motors done......woohooo Join Date: Mar 2002 Posts: 799	i would change your o2's like you said, thats usually the reason that a car that previously passed fails! your numbers are looking a little steep to just be the o2's though. try the o2's and go from there. this might sound like a stupid question but you do have the cats still on the car right? __________________ 95gt lazer red (98 cobra clone) Rice Haters Club Member #116

11-29-2002, 10:56 AM	#3
chuck88 Registered Member Join Date: May 1999 Location: Wood Ridge NJ USA Posts: 341	Yes I still have the stock cats are on. Chuck88GT __________________ So what if its "midlife crisis". Wife, 2 kids, busy job, "fixer upper" house, and I still have time for the Mustang!!! I Love my kids!!!

11-29-2002, 04:41 PM	#4
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	Did they also list the results for CO2 and O2? I can better tell you what's up when I have the results from a 4 gas analyzer. How warm was the engine when you had it tested, and is your smog pump still in place? __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

11-30-2002, 09:05 AM	#5
chuck88 Registered Member Join Date: May 1999 Location: Wood Ridge NJ USA Posts: 341	Smog pump is still in place. I drove the car for about a 1/2 hr temp guage read 180. NOx 0091 Standard =1378 HC 0258 Standard =0180 CO% 07.07 Standard =01.01 CO2% 08080 Standard =No #s O2% 03.80 Standard =No#s RPM 2420 Standard =No#s Due to my newborn son the car has been neglected and the gas may have been 2 months old will this effect emissions? Chuck88GT __________________ So what if its "midlife crisis". Wife, 2 kids, busy job, "fixer upper" house, and I still have time for the Mustang!!! I Love my kids!!!

11-30-2002, 03:08 PM	#6
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	Okay. I'm presuming that the CO2 percentage was 8.8%. If that's the case, I think you may be okay. Your results indicate an extremely rich condition at first, but when you add the CO2 and CO percentages, you come up with better than 15%, which is equal to an air/fuel mixture of about 14.2, which is excellent. Your CO2 is the result of the cat burning up the HC and CO. The higher the CO2, the better. Above 13% would be best. So, the results tell me that your engine is fine, but the cat system that is supposed to convert the HC and CO isn't doing it's job. However, the CO is greater than the O2, which usually means the cats are okay. Your main problem was that you didn't get the cats hot enough. You should be running a 192 t-stat, and getting the engine as hot as you can, without boil-over, just prior to the test. I like to recommend taking at least 30 minutes to drive to the shop, and keep it a gear lower than normal. Get that puppy HOT! Your cats are probably good for another year or two, but replacing them now would have a big effect. Take care, ~Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

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