93 toy p/u 4x4 engnbldr cam 261 valve timing set @ 7intake 9exhaust, engnbldr street head, lc header exuast, k/n air charger, matched injectors. stock plugs. 8mm wires

Failed the smog test for texas for the second time. the numbers are:

High speed Low speed

HC standard 194 mine 113 standard 199 mine 126
CO standard 2.19 mine .33 standard 1.69 mine .44
NOx standard 1258 mine 1474 standard 1378 mine 2205

I replace the EGR valve And the vacumm modulater, thermostat with a 160. i found the vacumm line to the modulator from the egr valve cloggeg. cleaned it up and stuck it back. on. pulled vac on egr valve eng when running at idle and it died so thats good.

What should i do next. i have passed the spending limit for this year 600 dollors so i can be exempt but i'll fail it next year i need to fix this.
thanks for your help

run two cats <img src="/forums/images/graemlins/lol.gif" alt="" />

too much hair <img src="/forums/images/graemlins/mrt.gif" alt="" />

Just checking to make sure you are saying that you drew vac on the valve(opening the valve), not that you simply pulled the vac line off of the valve.


Checked your O2 sensor lately? How bout your TPS? Oh how I hate EFI... grrr... :P


<img src="/forums/images/graemlins/cheers.gif" alt="" />

If you haven't already, try putting in fresh oil and make sure it's nice and hot before you get it tested. Run up and down a freeway a few times, then head to the smog station.

I know that I've failed a few times in the past, because I just drove straight to the smog station from my house, which is about 8 miles in town. But if I got the engine nice and warm with high speed driving, it passed.

yes i drew a vacumm on the valve

ttt help

To reduce NOx on my '85, I found retarding the ignition timing a few degrees helped, as did running a tank of premium gas (for the test). Also spent a day cleaning and porting out the EGR passages in my header and head plus the EGR plumbing and valve. My EGR would kill the engine with the simple vacuum test, but it seemed that there was not enough flow at the higher engine loads to be effective.

When was your last oilchange?

HC and CO can sometimes be fixed by doing an oilchange right before the test.

A 160 thermostat seems a bit low for passing smog, assuming all other systems are operational. I've always put in a 195 for the test then replaced it with the lower temp of choice after passing.