My vehicle failed NYMA emissions inspection criteria with the following emission inspection test result readings:
HC= 0.47 gpm (limit 0.80) CO= 17.82 gpm (limit of 15.00) NOx= 0.63 gpm (limit 2.00)
After replacing the EGR valve, the emissions inspection test result readings were:
HC= 0.62 gpm, CO= 31.48 gpm, and NOx= 0.51 gpm.
The catalytic converter was replaced next, and the emissions inspection test readings changed:
HC=2.93 gpm, CO=93.01 gpm, and NOx=0.22 gpm.
Can anyone explain why have the HC and the CO emissions inspection test readings become progressively worse, after replacing these (expensive) emissions control items?
Does a cat converter, specifically, the Toyota P/N 18450-62050, as used in my 91 Camry V6, function to reduce HC, CO, and NOx emissions, or is the function of the cat converter to filter and reduce only HC and CO gases ? (Some cat converters do not handle NOx gasses.)
Does an EGR valve, specifically, the Toyota P/N 25620-62020, as used in my 91 Camry V6, function to help reduce HC, CO, and NOx exhaust gas emissions, or does a properly functioning EGR valve help to reduce NOx gases only ?
Vehicle is 1991 Toyota Camry Sedan 2WD, V6-2507cc 2.5L DOHC (2VZ-FE) engine, driven within the NYC metro area (Long Island). .
I do not know what "gpm" units are, but is 17.82 gpm, which exceeds the test criterion limit by 2.82 gpm , a significant failure? Of what component(s) ?
Any comments?
TNX.