25/25
hc ppm 56 - 153 allowed
co % .00 - .86 allowed
no ppm 1113 - 1123 allowed
co+co2 % 12.4 - 6.0 min

50/15
hc ppm 46 - 159 allowed
co % .00 - .89 allowed
no ppm 2503 - 1242 allowed ---- heres the problem.
co+co2 % 11.9 - 6.0 min

hey H-T im new to the swap game. 94 ls stock. runs good most of the time. but when it reaches full temp. sometimes goes lean. or thats what i think. feels like out of gas. did return pressure line test. 8 oz in 10 sec. mostly hwy issues. around town you dont notice it. lots of new parts inc. plugs (ngk) wires, cap & rotor, o2 sensor, fuel filter. fresh oil and air filter. i borrowed an a/f ratio guage. when it acts up on hwy, gauge goes lean off the chart. I know its not a wideband. but sort of helped me find when the issue starts.

thanks in advanced

 

High NOx emissions are often from too much heat in the combustion chamber. Check your timing and cooling system.

 

thanks delsolproblems. the rad is new. but it is the stock eg hatch size. (1 row, 16 inches wide.) the mech timing is spot on. not sure but im @ 17 degrees btc? wondering why it would jump so high(nox) considering it passed the 25/25. does the ecu alter timing?

 

It only barely passed the 25/25 though. The amounts are about right. In the test simulating 50% power, the NOx amount is about doubled from 25% as it should be. It's just too high to start with. The ECU does indeed alter timing. This is why you have to jump the little connector under the dash before setting the timing- to keep the ECU from changing it while you're working.

16 degrees btdc

 

16 DBTC is the timing from factory. I had this issue and it was a alternative temp. thermostat that opens at 200F vs 170F from the factory. Also how old is your cat converter? If it is original, I would make sure it is heated up well before a smog test.

 

what's this 25/25 and 50/15. I'm in emission class right now and learning about all this. but the way it's taught in class looks a little different than what's posted.

NOx i was told is suppose to be 1000 ppm or less. Why does it say CO+CO2% 11.6- 6min?? what does that mean?

 

thanks for the replies. gonna check the t-stat today. cat is only 2 months old. just finished this swap, just to be sure... Is the rad to small for the b18?

 

If the radiator was too small, the fan would stay on continuously or else would be on most of the time- when it is warm outside and assuming the system is working correctly.

a97b18b:

25/25 mode- simulates 25% of the vehicle's power at 25mph
50/15 mode- simulates 50% of the vehicle's power at 15mph
(CO+CO2% 11.6- 6min) is the % of carbon oxides found (11.6%) and minimum allowed (6%). There needs to be a minimum or else people could just connect a fan to pipe under the car and have zero emissions. Any type of engine that normally produces less would be smog-exempt.

 

High NOx = running too hot or lean

For the possible lean condition, measure the fuel pressure, check the FPR and O2 sensor, and clean the fuel injectors.

 

ok y'all. i retarded the timimg (dizzy) and the nox dropped 500 points @ the 50\15.

DSP... i thank you for the rad info. checking the fuel system again. i noticed that the fuel line has been kinked in two spots, and then sort of straightened. you feel the dent or impression. could i just cut and flange this line? using a rubber line?

RonJ@ht... i do have some gsr injectors. can i clean them and place them on the ls motor? to reduce down time that is, my dd here...

 

!FIXED!


can you believe the fuel line got hit or?... during the transplant. WTF? it was damn near flat, about half inch long.

runs so good I pulled on a m3 2k model or so.