CHECK ENGINE LIGHT ON? DON'T PANIC!
Are you driving with your check engine
light on? Is it giving you anxiety?
Yes? Well, it really shouldn't.
Let's begin with the basics. At the
most basic level, the check engine light is telling you that there is
something wrong with your car's pollution control system. It could be
as simple as having the gas cap loose. Just re-tighten and the light should clear.
If that does not solve the problem, it will need further troubleshooting. Here is what typically your mechanic would do to figure out why the check engine light is on.
But before we get to that, you need a bit of background about what this pollution control systems are all about. Let's go back in time. Just about before the motor vehicle took over.
Before cars were very popular, people used to move about on horses and horse drawn carriages. As you know, horses need to eat, well, what goes in on one end, needs to come out the other. Things were so bad with horse manure that the streets were looking like this.
It got so bad that cities were in crisis with horse manure!
If you want to read more about that check it out here
Anyhow, when cars appeared, some people took them as a God's send, they weren't as bad as horses with pollution. But that wasn't accurate, cars pollute just as much but in a different way.
Horses use oats for energy, cars use petroleum distillates for energy like gasoline or diesel fuel. The energy used in a car is converted into work by what's called an internal combustion engine which looks like this cutaway.
The basic internal combustion engine works like a controlled furnace, it takes air. gasoline, and a spark and turns it into heat and work, in a four cycle process illustrated like this.
The ignition point is when combustion takes place.
Now, this combustion is not 100% efficient. And this is the problem. See, for every gallon of gas that is burned in an internal combustion engine it creates over 19 pounds of carbon dioxide!
See, https://www.fueleconomy.gov/feg/contentIncludes/co2_inc.htm LINK
What's worse, since the combustion is not 100% efficient, a lot of the hydrocarbons that are not burned are released as SMOG into the atmosphere where you get cars spewing fumes like this.
Pollution control engineers have come up with some solutions to try to control pollution, they are not perfect but they help in trying to clean up our environment. Before we move on, and to give you an idea of how much pollution we are talking about, here is some math:
There are over 6,000,000 registered motor vehicles in the State of New Jersey. A gallon of gasoline is about 6.3 pounds and produces about 19.64 pounds of carbon dioxide when is burned in a motor vehicle. If a motor vehicle uses about 5 gallons of gasoline a week that's about 31.5 pounds of gasoline, the pollution would be about 98.2 pounds of CO2. If you multiply that by the number of registered motor vehicles, you get about 589,200.000 pounds of CO2 per week! And if you multiply that by 52 weeks per year it is about 30,638,400,000 pounds of CO2 per year just for the State of New Jersey!!! Yes, that over 30 Billion pounds of carbon dioxide for one state.
http://www.eia.gov/tools/faqs/faq.cfm?id=307&t=11 LINK
http://blueskymodel.org/gallon-gas LINK2
Think about this, a tractor trailer gross vehicle weight is 80,000 pounds.
If we divide 30,638,400,000 pounds of CO2 per year / 80,000 that is about = 382,980 trucks of pollution just for the State of New Jersey in one year! Yeah, you get the idea.
Ok, anyways, here is what your mechanic does next to see what's wrong with your car and why the check engine light is on.
He plugs a scan tool they call a scanner that looks like this.
Into a port on your car called an OBDII connector that looks like this.
If the check engine light is on, the scan tool will display the codes that are active like this.
As you can see above, code P0155 is being displayed. Here this is a simple code and depending on your car, the repair can be less than $100.
Here for example is a list of different codes.
Here is where the complicated part of the troubleshooting process comes in, and if your mechanic is not well trained he could spend a lot of time looking for the problem that caused the check engine light to come on.
Now here is a secret master tip to know if your mechanic knows his stuff regarding gasoline engines, ask him "What is the stoichiometric air-to-fuel ratio of gasoline in my car?" He should tell you it's about 14.7 to 1. Here is a link for your to know what that questions means:
https://en.wikipedia.org/wiki/Stoichiometry LINK
All you are asking him is to tell you at what point is the mixture of gasoline to air best to take place in your engine for combustion in general terms. If he has trouble answering you, you should ask for a second opinion.
Ok, the whole point of this post is just for you to know that all the check engine light is telling you is that there is something wrong with your car's pollution control system. And that is very important to have it looked at sooner than later, because the longer you wait, the more expensive to fix the problem will become.
Here is an illustration and picture of one of the most expensive components you may have to replace if you keep driving with your check engine light on, which can easily cost you over a thousand dollars!
The above is called a three way catalytic converter, and it does a critical job of taking unburned hydrocarbons and nitrogen-oxides and turning them into less harmful compounds.
In you need to fix your car and to clear your check engine light, please give us a ring on 732.283.2469. Till next time, Deepa Auto Repair
