top of page

Check Engine/Malfunction Indicator Lamp


Check Engine Light or service engine soon light is the small light on your cars dashboard that usually says just that, "Check Engine" or Service Engine Soon". The Check Engine light is also know as a MIL or a Malfunction Indicator Light and depending on the vehicle manufacture, may simply have just a picture of a motor and no writing.
If this light does not come on when we turn the key on and go off in a few seconds, it fails the functional portion of the Smog Test Inspection. If the MIL comes on and stays on, then the vehicle fails the Smog Inspection. This light is an indication that there is a problem with your emissions system.
The MIL being illuminated does NOT indicate the computer is bad. In 20 years, Autotek has replaced less than 10 computers (ECM) in vehicles. Vehicle computers are known as ECM or Engine Control Modules and have very low failure rates. ECM's are routinely misdiagnosed and result in excessive repair cost for customers and potential new problems due to inducing a new variable into the complex and robust electrical system.
The most likely cause, of a Check Engine Light being illuminated, is a sensor out of range. The second most likely cause of a Check Engine Light illumination is, believe it or not, human error as botched previous repairs attempts cause a major portion of Smog Check failures. Our recommendation is to find a reputable licensed Smog Check repair facility to fix this problem as these repairs require extensive knowledge and robust equipment in order to accurately find failed emission components.


Evaporative Emission Control system known as the EVAP system, it is a bundle of different components, that combined, make a system. These components consist of a gas tank, fuel and fuel vapor hoses, a charcoal canister and valves or switches. If your vehicle has failed the functional EVAP portion of the Smog Check Inspection, then the functional portion of the inspection has failed indication your vehicle has a leak in the EVAP system. The failure could be a attributed to a simple hose or could also be an indicator of a larger problem such as a leaky O-ring on top of the tank or the fuel tank itself. It is very difficult to pin-point an EVAP system leak without having a smoke machine that can pressurize the EVAP system with traceable smoke that can be seen with a UV light.
Finding EVAP system leaks takes specialized equipment to pressurized and induce smoke and newer vehicle require complex scan tools that can activate the vehicles computer controls. For this reason, we recommended that the vehicles EVAP system be diagnosed and repaired by a Smog Check repair facility that has the complex specialty equipment.

Evaporative Emission Control (EVAP)


Ignition Timing

If your vehicle failed the Smog Inspection for the Ignition Timing out of specifications you will, at minimum, need to have your timing adjusted. WARNING! After changing the timing, the vehicles emissions levels will change. Sometimes they will get better sometimes worse. If you advance the timing, your NOX and HC will inherently go up. If you slow down the timing, they go down. There are variables to this rule, but this is usually how it works.

EGR Functinal

EGR Functional Test

EGR is an acronym for Exhaust Gas Re-circulation that is utilized as a system of parts to introduce measured amounts of exhaust gasses (burnt fuel vapors) back into the intake manifold of a engine. The objective of EGR system is to utilize the inert exhaust gasses and introduce the gas into the intake air charge in order to lower combustion temperatures below 2500 degrees. The importance of lowering the combustion temperature is to reduce and eliminate NOx gas that are created in the combustion chamber at temperatures above 2500 degrees.

Not Ready

Not Ready

"Not Ready" simply means the vehicle is not ready to be tested. 

Vehicle monitoring systems need to complete a specific criteria (Drive Cycle) in order for a Monitor to run. Vehicles have several Monitors and all makes and models have different amounts of Monitors.
Readiness Monitors will be in a Not Ready state after a vehicle repair, disconnecting a vehicle’s battery or by clearing the Check Engine light with a scan tool.

bottom of page