1. Current and Future Diesel Testing Mobile Sources Program Air Pollution Control Division

2.  Uses opacity as the pass/fail cut-point;  Does not receive SIP credit;  Started in the early 1980s in conjunction with the gasoline program as an equity issue;  Decentralized test network (private shops). 2

3.  Diesel Opacity Inspection Program (DOIP) ◦ Vehicle loaded on dyne and opacity measured  Max 20% opacity heavy-duty turbocharged;  Max 35% opacity heavy-duty normally aspirated;  Max 40% opacity light-duty. ◦ 4 model year exemption. ◦ >10 years annual testing. ◦ ≤10 years biennial testing. 3

4.  Self Cert Program ◦ Also opacity - J1667 (snap test)  Max 20% opacity heavy-duty turbocharged;  Max 35% opacity heavy-duty normally aspirated;  Max 35% opacity light-duty turbo;  Max 40% opacity light-duty normally aspirated. ◦ 4 model year exemption. ◦ >10 years annual testing. ◦ ≤10 years biennial testing. ◦ Must use a meter ≤10 model years – meter or visual after that. 4

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6.  A visual Inspection is also included: ◦ Pump seals ◦ Boost (turbo) ◦ Engine light ◦ Trap (OC/DFP) ◦ PCV ◦ EGR  Most common failures are for engine light and/or OC/DPF 6

7.  EPA and CDPHE commissioned a report (2001); McCormick, et al. ◦ Dyne loaded, mass based emissions measurements of 26 vehicles with visible smoke emissions; ◦ Seventeen pre-1991, and nine 1991 & newer vehicles; ◦ Twenty vehicles were repaired 7

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10.  For pre 1991 vehicles, repairs can reduce PM and CO by 55-60%, and HC emissions by 35-40%;  For pre 1991, NO X emissions increased by ≈35%;  For ≥1991, vehicles repairs reduced PM & Co by 25-30%  For ≥1991, NOX emissions increased by ≈7% 10

11.  “Clearly a significant reduction in emissions of air toxics can be achieved by repair of smoking vehicles.”  “Regression analysis indicates that smoke opacity is at best a poor predictor of PM emissions (r 2 =0.2).”  “It is recommended that an improved inspection and maintenance test procedure based on a tail pipe measurement of CO and THC during snap-acceleration be developed.”  “Twenty vehicles is not enough to base policy on.” 11

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14.  “There are currently no test procedures or equipment available to cost-effectively test these vehicles for the primary pollutants of concern, PM and NO X.” 14 St.Denis, Linder, December 2005, Air & Waste Management, Volume 55