I just had my car emissions tested. Failed the first time. I had nothing emissions related on the car, !AIR, !EGR, !Catalytic convertor, 160* thermostat.

NOx standard: 751
NOx emissions: 289/308

Hydrocarbon standard: 108
Hydrocarbon emissions: 172/233

CO standard: .6%
CO emissions: .88%/.82%

After the test, we installed the cat from my friends '95Z that had about 75K miles on it, put in a 195 thermostat, and nothing else. For the test we disconnected the fans to get the temp up to about 220, then plugged one back in to hold the temp. Results as follows:

NOx standard: 751 ppm
NOx emissions: 135 ppm

Hydrocarbon standard: 108
Hydrocarbon emissions: 33

CO standard: .6%
CO emissions: .02%

WELL below the standards, and with only a catalytic convertor and a PCMforless tune. Only other things done were new plugs and one new O2 sensor.

 

Nice information.....and a local speed shop rips my ear open about how Hotcam will never pass smog, even on my best day. Hmmm. Anyhow, thanks for the info.

Also, for those with 160 stats and thinking about taking them out for smog. I left mine in and passed. I had my car up to 230 degrees and the techie says I will not pass smog? I forgot what he said but one of the smog levels will shyrocket so I turned my manual fans on and he said it has to be around 195-200? I think it was NOx reading or whatever....is that true? Car too hot will give off higher readings? I thought it was good to have a nice high temp, I spent 15 minutes driving around the block and idling my car before I did the test so I can get it hot and he tells me no. Hot 195-200 is good but too hot is bad. So im confiused.

 

My HOTcam passed no problems. HOTcam, homeported heads, random tech cat, PCMforless tune and I was at a little over half the allowable emmissions.

 

where are you guys that passed with it located? im in ny. im looking at an inspection sheet from work at it says the limit is HC 0.60 gpm CO 10.00 NOx 1.50 will it pass with those limits. they seem to be differant than your limits

 

Honestly the numbers could be different, I got them over the phone with my dad, so it's just what I heard that I put here. But you get the idea, well below on all of them. This was in the "Houston Exclusion Zone" or whatever you want to call it. Supposedly they are going to get stricter in the next year or two.

 

Keeping a lower T-stat in will help reduce NOX, as well as keeping the EGR on.

Uncertain why anyone one would install a highier T-stat for the E-test ?

The hotcam will pass any emmission tests, even Cali's, easy without a PCM retune.

 

anyone feel they have a decent tune on their hot cammed LT4? I'm still working on mine, it does alright, but wondering if there is anything better out there. every once in a while mine will load up at idle, have to blip the throttle just a hair to get it back to normal, otherwise the motor will start choking on it itself, go wot w/ the iac, then calm back down till it decides to do it again.

 

My old hotcam setup passed with ease (better than stock) . Only emissions on the car was the stock cat.

 

raising the engine operating temp actually lowers emissions.

 

CC305 even passes easily in CA on a stock tune.

 

Raising engine temps may help HC and CO but not NOX.

IMHO I wouldn't want high engine temps on a car without EGR, not just for emissions, but for daily driving as well. Heat will have an effect on cylinder pressure thus increasing the chance for pre-ignition or ping under load.

 

Funny since my NOx emissions with the higher temp were almost half what they were for the 160 thermostat. The main reason we rose the temp though was to get the CO down. Getting even lower NOx emissions was just a nice side effect.

As far as your concerns around daily driving, the high temp was only for the test. As soon as it was back home, the 160 therm was back in it.

 

The PCM4less tune was the same for both E-tests ?

 

Exact same for the important stuff.

Only thing that was changed was the fan temps, but that didn't help either becuase something is messed up and the fans turn on just after the engine starts, so we disconnected one of them.

 

One is using ppm, the other (yours) is grams/mile.

BTW, here it's .80-15.00 & 2.00 for a 94-95.