Failed Emissions...BARELY! Can any help diagnose my problem?

[Siizzzoooo]

It is a 93 S13 coupe w/ 155k miles, the motor is a 97 KA w/ 90k miles, used 93 intake and exhaust manifold, so those have 155k as well

HC is 325, with 220 allowable
CO is 1.29 with 1.20 allowable

anyone have any ideas?

I think the timing may be slightly off, but I'm not sure what else it could be...maybe a misplaced or switched vacuum plug, but other than that I'm not sure...

Any help would be great!

-So

[Irukandji]

try changing sparkplugs, usually old plugs wont combust all the gas and nasty stuff comes out of your exhaust.

OR, when you did the ka swap, make sure you connected all the EGR stuff because the 91-94 ka EGR is different from the 95-98ka EGR.

check your cat as well.

[ka24deturbo]

Hummmmm o2 sensor, I had the same problem a while back. A member advised me to change my 02 sensor and I passed smog back then and I just passed it again a three days ago. Good Luck!

[NinjaGaiden]

spark plugs, wires, o2 sensor, I even changed teh timing chain and I still failed with too much hydro carbons.

I checked my ECU and it threw out an error code (dont remember which one it was), but it pointed at my EGR. If the above doesn't work, try cleaning out your EGR components. I didn't clean mine out, because the guy at DEQ liked my car and just revved it a little harder to make it pass.

[driftNWC]

i asked my friend who does emissions testing, he said run a bunch of fuel injector cleaner in the gastank as it is alcohol and burns MUCH cleaner then gas

[Siizzzoooo]

what do you guys think about running denatured alcohol?

[Pacman]

I would clean out your EGR and make sure thats working correctly. Then, A good tune-up w/new O2. Finally, change the cat and that should take you down levels. Take it in for pre-tests before doing each of these and look at what helped.

[kazuo]

The EGR wouldnt help too much with that, itll mostly help with NOX... I had like less than 10 on HC and CO with no EGR.

I would do a basic tune up (and make sure timing is set properly), run the highest octane gas you can get out of the pump, and get a new cat.

Then you should pass.

Most times, when people throw that EGR code on the ECU (32 I think?), its always the EGR solenoids causing it to go bad... but theyre pricey to replace and can only be had from the dealer.

Just wire the CEL to the Oil Pressure light. Problem solved.

Good luck

[RBS14]

For the HC, put 2.5 ounces of Acetone per 10 gallons in your gas tank, when you fill up for before your next smog. I went from 140PPM to 87PPM doing this. I added 4 ounces to a full tank in my S14. For me, this was much cheaper than getting a new cat, and worked great.

[SHIFT_control]

My old Celica failed by about the same margins that you did. Went back the next day with a full bottle of rubbing alcohol in my tank, passed with flying colors.... Reminds me I have to get that emmisions thing on my Pathfinder this week

[Bow]

For the HC, put 2.5 ounces of Acetone per 10 gallons in your gas tank, when you fill up for before your next smog. I went from 140PPM to 87PPM doing this. I added 4 ounces to a full tank in my S14. For me, this was much cheaper than getting a new cat, and worked great.


Was that before or after the ITB mod?

I would say Tune Up...

[RBS14]

this was on my completely stock daily driver.