I give up on emissions....failed for 3rd time!

[GSX20]

Ok, i am stumped. Here's the deal. My first try at emissions i failed HC (hydrocarbons) & CO (carbon monoxide) miserably. I bought an entire new exhaust sysyem (with high flow cat), a new downstream O2 sensor (had a CEL for it), new PCV valve, and i already had a fairly new upstream O2 sensor. I went back for a second try and had much better results, but still failed on the HC's and the CO. (HC's were at 1.86 and the limit is .060) Now this weekend i fixed a major boost leak at the throttle body and changed out my plugs. Then i drove it until i had about an eighth of a tank of gas and i added a bottle of isopropyl alcohol. Tested it again hoping the third time would be a charm and no luck! I passed the CO this time but i still failed on the HC's (the reading this time was higher at 2.33!) WTF

I know hydrocarbons is unburnt fuel, but i cannot figure out why mine is so high.
Can anyone help me out and give me some reasons as to what the causes of
hydrocarbons is. My registration is suspended and i already have 2 tickets for it.

My mods are in my profile with the exception being i do not have my MBC hooked up
(boost creep issues)

Any help would be greatly appreciated!

 

[jfdid]

If you're serious about it, replace your high flow, with a regular cat for the emissions test. That's my obvious .02

 

[ClevSilverEclip]

jfdid gives solid advice.

A factory cat is the way to go.

Even name brand "high-flow" aftermarket cats often lack enough catalyst to get our DSMs past some of the more stringent tests.

To give you an idea, switching from an aftermarket high-flow cat to the OEM Mitsu, my emissions for CO and HC both went down to 0 (zero!) from what were otherwise low and still passing numbers.

-A
/

 

[swarm]

Guess I'll take one for the team. I will trade you your '99 GSX for a '96 Neon SOHC. It's guaranteed to pass emissions.

But... I guess that's not an option, so add an OEM cat to your exhaust

 

[fp-green-95tsi]

Don't go puttin the stock cat back on yet! I have passed with hi flow cats on all my cars. Hell even passed with no cat before. Do you by chance have an aftermarket fuel pump installed on a stock regulator? How about an afc or any kind of tuning device to lean the car out?

 

[GSX20]

The fuel system is stock right now. I don't have a SAFC. The thing is when i failed miserably the first time it was with the stock exhaust, including the stock cat. When i went the second time after having my 3" turbo back with high flow cat installed the numbers were much improved. So i don't think the cat is the issue.

 

[fp-green-95tsi]

Is your bov venting by chance?

 

[Game Over]

Your stock cat could have shit the bed and you didn't know it...

 

[booosting92tsi]

well if you have an AFC, don't lean it out too much, then the engine might run hot and fail NOx, Here in Philly, PA we don't only have HC and CO testing but also NOx. Pain in da butt

 

[ClevSilverEclip]

well if you have an AFC, don't lean it out too much, then the engine might run hot and fail NOx, Here in Philly, PA we don't only have HC and CO testing but also NOx. Pain in da butt

You know, that's definitely a good idea - and one that I've been playing with in my head, too.

I think that this might be worth a try for me, as the only problem with my current emissions is NOx.



---------

GSX20 - I, too, am wondering if then perhaps your stock cat is shot...... ?

-A
/

 

[4g64GST]

what brand high flow cat are you using, maybe a part number??

I wholesale converters and exhaust is why I am asking.

 

[GSX20]

Is your bov venting by chance?

bov is reirculated

 

[GSX20]

what brand high flow cat are you using, maybe a part number??

I wholesale converters and exhaust is why I am asking.

I'm using the Extreme Motorsports 3" high flow cat
Item # EXM0213

 

[GSX20]

You know, that's definitely a good idea - and one that I've been playing with in my head, too.

I think that this might be worth a try for me, as the only problem with my current emissions is NOx.



---------

GSX20 - I, too, am wondering if then perhaps your stock cat is shot...... ?

-A
/

you guys need to read my original post more clearly........i don't have a stock cat anymore. I had it for the first emissions test, then i got the new exhaust put on.

 

[ClevSilverEclip]

you guys need to read my original post more clearly........i don't have a stock cat anymore. I had it for the first emissions test, then i got the new exhaust put on.

No, no, that's not what I meant - and if I understand you correctly, you failed the first time, horribly; then went back with the aftermarket cat and failed yet again, correct?

I'm wondering if what made you fail the first time was because your stock cat was completely shot. Later, your switch to the aftermarket caused you to fail w/a smaller margin was then because it didn't have enough catalyst.



-A
/

 

[GSX20]

No, no, that's not what I meant - and if I understand you correctly, you failed the first time, horribly; then went back with the aftermarket cat and failed yet again, correct?

I'm wondering if what made you fail the first time was because your stock cat was completely shot. Later, your switch to the aftermarket caused you to fail w/a smaller margin was then because it didn't have enough catalyst.



-A
/

Oh, ok.....i see. Anyways, i can't really go back to a stock converter because i'm pretty sure they don't make a 3" oem one, and i sure as hell am not buying a brand new oem exhaust!

I just need some reasons why my hydrocarbons are so high. I'm using Ngk BPR7ES plugs. Maybe i should switch to BPR6ES? New plug wires? What else could be a cause for the A/F mixture to not be completely burned?

 

[Game Over]

It very well could be the lack of stock plugs.

 

[93awdhaitian]

Or you could always move to Florida. B/c I know none of our cars would ever pass.

 

[Talesin]

Could see about getting a bolt-on OEM cat with flanged 2.5"-3" expanders welded to either end, making it into a bolt-on, much like a testpipe. Sure, you'll have constriction. Toss it on when you're going in for a test, and let it sit in the closet the rest of the time. Make sure to put it on two weeks or so before the test, just so it can 'settle in' and get used to being hot again. What I'm considering doing with my Mirage, as the aftermarket knockoff cats seem to core out for some reason... from what I was told, they're good for about one year of normal operation.

 

[ClevSilverEclip]

Could see about getting a bolt-on OEM cat with flanged 2.5"-3" expanders welded to either end, making it into a bolt-on, much like a testpipe. Sure, you'll have constriction. Toss it on when you're going in for a test, and let it sit in the closet the rest of the time. Make sure to put it on two weeks or so before the test, just so it can 'settle in' and get used to being hot again. What I'm considering doing with my Mirage, as the aftermarket knockoff cats seem to core out for some reason... from what I was told, they're good for about one year of normal operation.

I'm going with this idea, too.

My lawyer makes me say that this is not what I would do, however.

-A
/

 

[GSX20]

I hate to resurrect this thread but i finally passed emissions. I recently got an safc and went to test my car the other week, but the manager wouldn't let me retest because of my open element air filter. So today i put the stock air intake back on and i leaned out my low throttle settings -7% across the board. Passed all three emissions easily. I didn't swap out my high flow cat either. Just wanted to post what finally resolved my problems. Thank God this mess is finally over.
Now i will register in a non-emissions county and be done with this crap forever!

 

[HighPsi92GST]

Good

 

[eclipsegsx1736]

Did you hide your SAFC? I'm wondering if you could fail if the guy performing the test saw you were deliberately altering the fuel mixture just for the test.

 

[GSX20]

Did you hide your SAFC? I'm wondering if you could fail if the guy performing the test saw you were deliberately altering the fuel mixture just for the test.

Yes, i hid it between the passenger seat and the center console. They probably still saw the wire coming out through the center vent, but they didn't say anything!

 

[otiosity]

Man, this is one of those times I'm glad I live in Mississippi and dont have to pass an emissions or smog test. They don't care what you do to your car, as long as lights, blinkers, horn, and windshield wipers work and you can get an inspection sticker.