Emission testimony to TH 3inch cat

[justabuickv6]

My 87 GN with 97,000 miles inspected today. I wanted to see if it would first pass with the TH cutout.

High Speed (25) Test

Standard Current Reading Result
HC(ppm) 144 111 Pass
CO .92 .56 Pass
CO2 6.7
O2 20.7
NOX(ppm) 1014 1836 Fail
Dilution >6.0% 7.3% Pass


Low Speed (15)

Standard Current Reading Result
HC(ppm) 148 126 Pass
CO .83 .55 Pass
CO2 6.8
O2 20.5
NOX(ppm) 1014 1991 Fail
Dilution >6.0% 7.4% Pass


Since it failed, I went home and installed a brand new TH 3 inch cat from Ramchargers which I already borrowed from my buddy. Here are the results.

High Speed (25) Test

Standard Current Reading Result
HC(ppm) 144 31 Pass
CO .92 .01 Pass
CO2 7.3
O2 20.8
NOX(ppm) 1014 201 Pass
Dilution >6.0% 7.3% Pass


Low Speed (15)

Standard Current Reading Result
HC(ppm) 148 34 Pass
CO .83 .02 Pass
CO2 7.5
O2 20.8
NOX(ppm) 1014 185 Pass
Dilution >6.0% 7.5% Pass


Something I didn't know. If it takes the full time for each test, which is approx 90 seconds, it will probably fail. If each test only takes about 15 or so seconds, it will probably pass in the end.