I am so excited about this that I tell just about anybody who will listen! I try to be careful that I don't repeat myself to the same person but this secret is so exciting that I just can't help telling everybody I meet. It's not really a secret. I'm sure lots of people know this but I just discovered it and I'm sure there are lots of people out there who still don't know about it. I know that no one I talk to knows about it.

Until about 3 years ago, I paid big auto repair bills. I drive a 10 year old car and about once a year it would gradually start running rougher and rougher. It wouldn't be very noticeable at first but it would gradually get worse and worse. For a few days it would be hardly noticeable while driving but at red lights, the engine idled roughly. After a couple of days, the check engine light would come on and then, after a couple more days, it would get so bad that while stopped at red lights, the engine would vibrate so badly that I was afraid the car would die right there on the spot. I could just imagine hundreds of cars piling up behind me as I tried to get it started again.

So to prevent breaking down on a busy road, I'd make an appointment at a car repair shop. I always went to a Ford authorized repair shop a couple of miles from my house. It was probably more expensive than some garages but I figured, being the authorized Ford repair place, they'd know what they were doing, charge me a fair price, and do a good job.

I'd go to this repair shop and they would take the car around to the garage and eventually get around to diagnosing the problem. The way it worked at this particular shop is that the mechanic would make the diagnosis and pass the information to a shop manager who would relay that information to me.

I would stand at the counter as the shop manager listed the things that needed to be done. And it was never one thing that needed to be fixed. It was always a combination of things, some absolutely necessary, some optional but urgently recommended, and some that could wait if necessary. And because I'm not a mechanic, I had no choice but to take this person's word for it and fork over the money. I thought it was just the way it was. Each visit cost from $600 to $900 bucks. Afterwards the car would run fine for another year. This scenario repeated itself three years in a row.

Ok. Here's what I was getting to. One day I was surfing the web and happened to stumble onto an article about auto code readers. The same diagnostic software that the auto repair shops use to determine what's wrong with your car is available at Sears or other stores and it costs less than a hundred bucks! Although the repair shops use a laptop, the home-use versions are small, hand-held units about the size of a multimeter. The article said that, using the meter, I could diagnose my auto problems myself. Well, I thought I'd give it a try. The next time I was at Sears in the hardware department, I looked around and found they stocked two different models --one for about $50 and one for about $100. They both did basically the same thing according to the box but I went with the more expensive one just to be sure.

A few months later, my car started to run rough again and the check engine light came on right on schedule. But this time, instead of going to the shop, I tried out my new meter. I followed the instructions that came with it and plugged it into the car's data plug under the dash. I turned on the ignition and after 10 seconds, an error code appeared on the meter's screen. Error 303. I looked up the code in the little book that came with it and it corresponded to "cylinder 3 misfire detected".

I had no idea which cylinder was number 3 so I bought a Haynes manual for my model car from Advance Auto Parts. It cost about $20 which seemed high to me but I needed it. And the information it provided was invaluable. The Haynes book detailed everything about the car including which cylinder was number 3 and what kind of plugs it needed and how to replace them. I bought a new set of spark plugs ($12 for all 6 plugs) and replaced all of them. It took me a couple of hours because it was my first time changing plugs for this car and I had to run to the auto parts store to buy a socket wrench extension to reach one of the plugs. But afterwards the car ran like a Swiss clock!

Boy, I was proud of myself. I would have ordinarily had to pay $800 to get my car fixed but I had just done it myself for almost nothing! And my car continued to run smoothly for another year! It dawned on me that those car mechanics had probably done nothing more than replace a spark plug to fix my problem and charged me $800 for the privilege!

After about a year, the car began to run rough again -just like before -and after a couple of days of that, the check engine light came on again. I nursed the car through the week and on Saturday I used my meter again. It showed the same error as last time: "cylinder 3 misfire detected". I forgot to mention that the previous year, when I changed the plugs, I noticed that the plug in cyclinder 3 was fouled. It was covered in oil. I'm no mechanic but I thought that maybe I had worn rings in that cyclinder that was allowing oil to seep past and foul the plug. But I had replaced all the plugs just to be sure.

This time, I checked cylinder number 3's spark plug and sure enough, it was fouled again. I compared it to the chart that was inside the back cover of the Hayne's manual to be sure. So I bought a new spark plug and replaced the number 3 plug. The car ran like a fine Swiss timepiece! Total time invested: an hour. Total cost: $2 (for the sparkplug).

I felt even better than last time! I fixed my car again!! I felt like driving over to the Ford authorized repair shop and giving them the finger! It was apparent that they had been ripping me off in the past. Those distinguished shop managers had lied to my face and robbed me. No more. I was no longer a slave to some guy who told me whatever he felt like!

I have replaced the same cylinder 3 plug for the third year in a row now. My cousin told me that it's possible that I don't have worn rings, that I might have a bad spark plug wire for that plug which doesn't deliver a hot enough spark to keep it clean. So next time the problem reoccurs, I will replace the spark plug wires and see if that fixes the problem.

I strongly recommend getting one of these meters and saving yourself big bucks. Every car has a data plug right under the dash, as conveniently reachable as the parking brake. You've probably not even noticed yours. Mine was covered with a small plastic panel that snaps in and out. You don't have to be a mechanic to use this little device. I'm not. And the Haynes or Chiltons manual, which are available at any auto parts store, tells you everything you need to know.

A bonus is that this meter can turn off the check engine light! You just hook it up to the car's data port and click on the erase button. It won't hurt the car because if you really have a problem, it will cause the related sensor to trigger the check engine light again. I've saved two friends at least $50 each because the dealership told them they would need to buy a new gas cap to correct the problem. Those were Toyotas. Apparently that wasn't true because they run fine with their old gas caps and don't get the check engine light any more.

There are several brands and models of the OBD2 code readers but they all do about the same thing. I recommend buying the cheapest one you can find. These code readers work on any car, foreign or domestic if they were built after 1996. Before that year the auto industry wasn't standardized and used various diagnostic software in their cars so if your car is older than 1996, read the fine print.

Don't be intimidated by ads for these code readers that show them hooked up to computer monitors. Although some of the more expensive models may have the ability to transfer data to a computer and display it, the computer isn't necessary. That's just an impressive feature. Mine has that capability (I think) but I've never used it. All you need is the meter. I'm glad I didn't see those ads before I bought mine because they might have stopped me from buying it. Using this meter is not complex. It's 1-2-3 simple. More information on using a code reader