I'm having a bit of difficulty getting the nox down on this ciera. 1992 3.3l non egr --came in with new cat, o2 sensor

readings at asm pre cat hc 132ppm co .59% co2 12.2% o2 2.6% nox 2993ppm

post cat hc 40 co .04 co2 14.1 nox 1852

some scanner readings a... Login to read more.