High Altitude Study

Some vehicles have high fail rates with the I/M 240 emissions test. Part of the reason has to do with Denver's mile-high altitude. This study was an effort to examine vehicles with a high failure rate to find out why, and, more importantly, to find out how to effectively repair them.

As part of its contract with the State of Colorado, Envirotest Systems commissioned and funded the High Altitude Study, which was conducted by one of the state's premier authorities on I/M 240 repair strategies. Chris Chesney, president of Diagnostic Technicians Educational Consultants (DTEC), has trained hundreds of repair technicians in FIRST and EDGE I/M/ 240 repair techniques, and has also conducted this training in other states where the I/M 240 emissions test is used.

Read Chris' summary article on the High Altitude Study, published in the April 1998 issue of Air Care News .

The Study Report:

Part 1: High Altitude Project Profile
Part 2: Project Methodology

The Vehicle Families Studied:

Part 3: 1982-86 Chevrolet LDGT 5.0/5.7L; Non-Feedback Quadrajet
Part 4: 1983-85 Ford LDGT 4.9L; EEC-IV Feedback Carburetor
Part 5: 1984-85 GM/Jeep LDGT 2.8L; Non-Feedback Varijet
Part 6: 1984-85 Low Altitude Honda Accord; Carburetor Feedback System
Part 7: 1985-89 Imports: Hyundai, Mitsubishi, Plymouth; Feedback Carburetor System
Part 8: 1983-87 Toyota Tercel; Computer Controlled Emissions

Chris Chesney is the owner of Diagnostic Technician Education Consultants (DTEC), 5497 S. Danube Way, Aurora, CO 80015. He can be reached at 720-870-6761 or via email at chesneydtec@cs.com. Chris has trained hundreds of technicians in I/M 240 diagnosis and repair.

For more information, call the Air Care Colorado Hotline at 303-456-7090. Se habla Español. Site updated 1/31/03.

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