Smog issues

[rocket455]

So i need to smog the SHO and visual passed *whew* but turned out to be a gross polluter when it came down to the emissions test.
15MPH %C02 measured:12.9
%O2 measured 2.71
HC(PPM) MAX 77 GP 283 measured 297
CO(%) MAX 0.50 GP 2.21 measured 0.01
NO(PPM) MAX 537 GP 1957 measured 0590

Results G POL

25MPH %C02 measured:13.2
%O2 measured 2.54
HC(PPM) MAX 58 GP 233 measured 233
CO(%) MAX 0.40 GP 2.08 measured 0.18
NO(PPM) MAX 494 GP 1757 measured 0429

Results FAIL

on a side note they offered to diagnose it. so they did and the cylinder balance test came back fine but the compression test was off

Cylinder balance test

CYL A 83%
CYL B 95%
CYL C 100%
CYL D 95%
CYL E 85%
CYL F 78%

PASS

VIRTUAL COMPRESSION TEST

CYL A 100%
CYL B 70%
CYL C 90%
CYL D 85%
CYL E 100%
CYL F 100%

FAIL

any input as to what would cause those emission results?

 

[deercrusher]

you probably need a new exhaust valve in whichever cylinder correlates to cylinder B. That would cause your high HC readings and your lower compression in that cylinder. For good measure change your spark plugs too.