Need help in trying to smog near Stock TTA

[davege]

I took my TTA (4656 miles) in for a the smog test a couple of weeks ago here in California and failed.

Here are the results:
15MPH
RPM 1519
%CO2 13.4
%O2 0.9
HC MAX 114
HC MEAS 184
CO MAX 0.73
CO MEAS 0.37
NO MAX 785
NO MEAS 144

25Mph
RPM 1507
%CO2 14.0
%O2 0.3
HC MAX 88
HC MEAS 121
CO MAX 0.61
CO MEAS 0.26
NO MAX 724
NO MEAS 22


I run 100 Unleaded gas in the car all the time and use stabilizers. Now the gas could be a couple of years old, but the car idles ok and seems to run ok. I just changed the oil before the test (Redline 10-30).

Stock fuel presure regulator (Measured 46lbs with vacume line off and 38 lbs with line on), stock airbox and 160 deg thermo.

I ran the test with a TurboTweek emissions chip.

Questions:
Is old gas enough to cause the HC numbers to be so high? I have run the old gas down to about 1 gallon and put 10 gallons in of VP 100 Unleaded with stabilizer and Redline SI-1 injector cleaner (concentrated dose) for the next test.

Will the new gas be enough? How much should I drive the car before I can retest?

Do I need to put an adjustable fp regulator on and set fp to lower pressure? If so, what pressure?

Do I need to replace the 160 deg thermo with a 195 unit?

Last question do you think the cat is bad?

Than you for any help on this.
- Dave

 

[davege]

Any one with experience around this?
-Dave

 

[Mac in SD]

Just one thought - I wouldn't run 100 octane for a smog test. High octane fuel burns slower than lower octane, so that may contribute to your high HC.

I would also throw in 2 bottles of HEET to a half tank of gas. If you can, borrow a known good cat before you try again. The 160 t-stat doesn't help, either, but I've gotten through with one before. Oh, yeah...did you put in fresh spark plugs? I really think the 100 octane is hurting you.

HTH.

 

[davege]

Mac,
Thanks for the suggestion. I will drain the 10 gals of 100 octaine unleaded and put in a 195 deg thremo and try the HEET and take the car in for a pre-test. I would like to find out if my Car if shot. Is my FP too high?

Thanks,
Dave

 

[norbs]

Get the thermostat in and beat on the car a bit to heat up the cat. The hotter the cat the better it will work.

 

[Mac in SD]

Mac,
Thanks for the suggestion. I will drain the 10 gals of 100 octaine unleaded and put in a 195 deg thremo and try the HEET and take the car in for a pre-test. I would like to find out if my Car if shot. Is my FP too high?

Thanks,
Dave

Dave,
I don't have much experience with TurboTweak chips, but I seem to remember reading on this board that they have some specific FP instructions. Maybe check with Eric at Turbotweak?

Again, good luck!

 

[davege]

I checked with Eric and he said I should be around 38 lbs with the vacuum line disconnected. I will have to install and adjustable FP regulatior as well.

- Dave

 

[iwantatta]

I alway run 1/2 tank VP 109 and 1/2 91. Got my TTA smogged about 7 months ago. Had the hotter Tstat, Stock Chip, Stock FPR, changed oil, and spark plugs. Have done this for 2 smog occasions so far and its passed both times at Test Only stations. Have put about 3000 miles on it the last 4 years so it does sit around at times.

Still original cats on it. Race gas at least with my mixture has so far has not caused me any problems with smogging.