Hi all, finnally i got my new hho kit installed on my honda stream 2.0 vtec and it seemed to work quite well beause setting the pwm at very low level it bubbles quite fast.

Altought i haven´t had time enought to notice any power or consumption improvement the check engine error has appeared in my dashboard , the error is p0420 , i haven´t been modifying anything else like o2 sensor , i just installed the kit. Why this should this be affecting the to the cattalyst efiency??? this error becomes from the second o2 sensor , am i right???

Thanks a lot!!!.