I tested a cat converter on a 1990 chevy sub with 7.4l,tbi fuel [...] cranking and 02 test.

cranking results are = hc 1944ppm, no 84 ppm, co .09%, c02 4.6%,02 16.6% 02 snap = hc 2000ppm, no 740 ppm, c0 3.91%, c02 9.4%, 02 3.0 %.

cranking hc reading read wa... Login to read more.