hey all i have a 94 dx with a b16a in it, i get a cel 23, the knock sensor. it seems like the lights will only go on at higher rpms, i reset the ecu so i could try to pass echeck, i failed because of high nox readings. if i replace the knock sensor will that help my readings?

 

Probably not.

What were the other pollutants reading? Failing on NOx but with unusually low HC and CO means it's running lean. If all 3 numbers are high, the cat converter probably needs to be replaced. Also if equipped (California version), the EGR system may not be working.

 

Does the ECU match the engine? What B16 engine? Do you have a knock sensor?

 

the other readings were fine, at acceptable levels... the ecu is p30 with b16a ii...i do have a knock sensor and it is wired

 

Acceptable, yes, but how do they compare to normal / average? If you run lean, the CO and HC will go to near zero, which seems great, but it'll fail NOx. So the other readings can be a useful clue for why NOx was too high.

 

my hc was 59.6 and the limit is 167.0.... my co was .03 with a .94 limit.. my nox was 1975.4 with 1240 limit...thanks