Smog Lambda Calculator

Smog Repair Technicians,

For speedier and more accurate smog data analysis, try the Smog Lambda Calculator app. It’s free and it should help all smog technicians do their work better and with less hassle.

This app was created by a Certified ASE Master Technician.


This Lambda calculator is DCF compensated. The Calculator is designed for Smog Check VIR printouts and 5 gas emissions readings.


Rich or Lean???
Example set of readings :

HC: 297 ppm CO: 8.49%
CO2: 9.93% O2: .15%

Here, lambda was 0.77, indicating an extremely rich mixture. These are tailpipe samples from a vehicle with a faulty (open) coolant temperature sensor.