Hi all,

Took my Turbo to get smogged so I can register the car in California.

The test results:

HC (PPM)
Max 100
Average 17
Measured 59

CO(%)
Max 1.00
Average 0.00
Measured 1.57

The technician who conducted the test said it could be my O2 sensor. But I don't want to go on a wild goose hunt before I consult with you guys.

Relevant mods on the car:
Tubi exhaust
Softronic ECU flash
Forge diverter valves

Would switching my ECU back to the stock setting change anything emission wise? Or should I hunt for a stock exhaust? Any advice is greatly appreciated.

 

Get your car good and hot before taking it in for testing. Bake the crap out of the exhaust. I also reset my flash to stock.

With my aftermarket setup, it didn't pass the 1st time either with the flash.

Reset flash to stock tune
I went and drove for about an hour and then at no less than 3500 rpm for the remainder of the drive (10 minutes) to the shop. Passed by a large margin.

Just something to try.

 

Thanks for the advice!

The car was already in operating temperature (did a couple of freeway pulls) before I took it in. The smog tech also revved the engine to ~2700 rpm for about 3 minutes before inserting the probe into the tailpipe.

I did a bit more research, looks like I either have failed cats or the 100 cell (?) cats on the Tubi won't pass the strict Cali emission test. What's troubling is that at 2262 RPM, the car had a CO output of 2.26 when the maximum allowed is 1.00. If what I read is correct, high CO output equates to issues with the cat.

With that said, anyone local (SoCal) want to sell me/lend me their stock exhaust so I can pass smog and register the car?

 

I'm too far [Vallejo] or I would loan you my exhaust. You DO need another exhaust with decent cats and those 100s aren't making it. You might want to start a new discussion asking to borrow a stock xst in SoCal. I think you will get lucky. You might consider just buying one as they are out there and incredibly cheap.
Good luck and enjoy
JR

 

John, thanks for the advice. Just PM'ed a Mod to see if I can get an one time exemption to post a WTB ad since I have less than the required 100 posts. Fingers crossed that I can pick up a stock unit soon and pass the test.

 

If there is a performance shop near riverside, see if they have stock system you can use or have.

 

many exhausts with 100 cell cats won't pass CA smog, especially if there is some mileage on the exhaust. you can go to vision in OC- they have a machine to test your emissions and if need be, they have many stock exhausts in house that they will install for you for the emissions test.
for reference, i have an exhaust with 200 cell cats (speedtech), that easily passed ca smog after using it for a year.

 

NOLA911 and OCTurbo, you guys are life savers!

Per OCTurbo's suggestion, I just called Vision and they have a bunch of stock 996 Turbo exhausts around. They can fit me in on Thursday, put the stock exhaust on and do an onsite smog check for me. Hopefully this will be the ticket to passing the dreaded test. Thanks again!

 

My car passed fine with the Remus exhaust (100 cell cats and GIAC flash). You can borrow my exhaust but you have to promise to bring it back... I'm in Topanga Canyon.

I suggest you find a friendly smog station if you know what I mean. I'm not the biggest fan of putting parts on and removingthem for a day.. Any savings will be used up the labor

 

Ari, thanks for the offer. Vision said they have a bunch of 996 Turbo exhausts laying around. So I'll just borrow theirs (or buy one if the price is right) for now and see if it is indeed the Tubi exhaust that is the culprit.

The smog tech today was convinced that it is failed O2 sensor(s). I don't think I've read many incidents of that with the 996 Turbo.

Just by numbers along, would anyone be able to say whether it is just the 100 cell cat or if it is other issues?

Idle
%CO2: 14.2
%O2: 0.0
HC(PPM): 59
CO(%): 1.57

2262 RPM
%CO2: 13.6
%O2: 0.0
HC (PPM): 34
CO (%): 2.26

 

Your issue sounds like either:

-exhaust not HOT enough before the smog test
-poor quality 100 cell cats
-boost/vacuum leak screwing up O2 control
-flash issue allowing the car to run too rich
-too old O2 sensors but that's very rare

How many miles do you have on your car?

 

If you find out it is indeed your exhaust, many people on this board like Tubi, just sell your 100 and buy a 200 and call it a day (unless you don't mind doing this every 2 years).

 

You should not need to change out the exhaust. Just put the flash back to stock and heat up the cat really well. Try this first at another shop before changing out the exhaust.

 

Move out of Communistfornia is my advice.

 

35k miles on the car, hence the reason I was so suspect when the tech said failed O2 sensor(s) is the reason.

I am taking the car to Vision first thing tomorrow morning. If swapping out the exhaust solves the issue, I might just get rid of the Tubi instead of go through this exercise every 2 years.

Will also bring my laptop with me in case I need to revert the flash back to stock.