Emission Controls: The Past 40 Years

Automotive emission controls became a hot button issue in the 1970’s. Manufacturers, faced with the challenge of reducing emissions, added devices like Exhaust Gas Recirculation valves (EGR), Catalytic Converters and designing leaner running engines. These were the first serious efforts to reduce tail pipe emissions.

In the process they reduced something else as well, power. The early EGR System was the main culprit causing vehicles to idle rough and reducing power and fuel economy. The design at the time did not work well with leaner running engines. It was not a great time to be a new car owner.

As the EGR system functions advanced, GM introduced the High Energy Ignition System (HEI) around 1975. The new transistorized system was able to create the spark needed for more efficient combustion in a leaner atmosphere. This did not create power but was able to maintain what was available by design.

I was working at a GM dealer at the time. We began to see some interesting things customers were doing to add power to their new cars. Like taking off the Catalytic Converters, disabling EGR valves, turning air cleaner lids upside down and inducting water into the intake. Not much help increasing the power, but when time came to trouble shoot engine problems, those efforts usually did increase the cost of repair.

The power issue remained for several years. In 1981 halfway in the production year, GM introduced the first Electronic Control Module (ECM), later know as the PCM (Power Control Module).

It did little to restore power despite the fact that the first ECM (it was said) was 15 times more powerful than the computer on the Lunar Landing Module. It was however a “giant leap” towards reducing tailpipe emissions. It monitored several parameters and even tried to make us aware of potential problems.

Introducing the dreaded “ Service Engine Soon” (SES) or “Check Engine Light” (CEL). The problem wasn’t the fact that the car had the light or that the light came on, the problem was that the public didn’t understand or care about the purpose of the light.

When a customer brought their car in for service and you saw the red glow behind electrical tape or a business card, you knew that there was a trouble code stored. When it was brought to the customer’s attention that the code should be retrieved and diagnosed more times than not, the reply was “That is just another gimmick from the dealer so they can make more money”.

What they didn’t realize was along with affecting the ability of the system to reduce tailpipe emissions; it was also having a negative impact on their fuel economy and the resale value of their car.

It created a problem for technicians as well. Along with the education and the price of tools needed to communicate with the On Board Computer, you could pop the hood on any given car and it looked like there was enough vacuum hose to circle the Earth.

Just about the time I was beginning to think I had made a poor career choice there was a light at the end of the tunnel, Fuel Injection. Not only did I see under the hood vacuum hoses reduced to as few as two, we got that power back in a big way.

Case in point: a little old lady, Mrs. Bond, had an old Buick, the proverbial boat anchor her son-in-law called it the battle star. It did not have a lot of power but she loved the old car even though it was getting past its prime. Her daughter was buying a new car and decided to give mom her Cutlass. It had a V6 multiport fuel injected engine. I checked the car out, we put a new belt on it and sent Ma Bond on her way.

The next day she called me up concerned that the new belt must be loose because she heard squealing sometimes when accelerating. I told her to come on down and let me take a look and when she arrived we popped the hood, finding no issue there, I told her the belt looked fine and to let me know if the noise occurred again.

We said goodbye and as she accelerated onto the street I heard the noise. The little old lady was smoking her tires, well not really smoking, but that was the noise. Of course she heard it too and came back immediately “did you here that?” “Yes” I said, and after telling her what it was we had a good laugh. She said “I was just used to having to gun the old battle star, I guess I’ll go a little easier on the pedal.”

Many years have passed since then and we have seen a lot of changes in technology. Most of it is for the good. I have an opinion however about how necessary it is to have a computer controlling your lights, wipers and windows right now.

I suppose though, these technologies may be laying the foundation for the day when you get in your car and say “Betsey take me to work”. Then the new problem may be that your window displays are not working and instead of seeing your favorite TV show, news channel or 360 scenic displays, you will be stuck seeing where you are and some little light on the dash. My guess is, that one won’t get covered with electrical tape.

Lance Campbell