Preferred obd reader / scanner?

My goal in this case is to avoid the mechanic if possible (i like my mechanic) when the check engine light is on.

What are your experiences with consumer OBD scanners / readers?

In particular, for the occasional (1-2/year) use, would a very basic (like an actron 9125) be more appropriate than a more full-function scanner (innova 3100?)?

Those are just a couple of examples from ads.

Thank you in advance for your feedback.

I’ve used the Actron OBD II scanner since 2000. The model that I have is the CP9035. It does the basic of pulling the trouble codes and erasing them. It will pull P codes for powertrain, B codes for body, C codes for chassis and U codes for Uart. I paid $168.00 in 2000. I’ve got my money back several times over since getting it. Very easy to use.

You can also go to one of the many major parts stores that will pull these codes for free.

Of the newer ones that Actron has I think If I had to buy another one I would buy the model CP9135 for $65.00 through at this site

This one also shows what the code means right on the screen were on mine I have to look at a manuel to see what each code means.

For even more “bang for your buck”, you could use those scanners that you connect to your laptop, or desktop, pc computer, or a Palm Pilot. With these, you can see what some of the sensors, and actuators, are doing on graphs…which you can print out. Price: $100, to $200, to $300, and up.

I bought an actron CP9145. It’s more expensive than other models, but you can use it to read data from the sensors. For example, it displays the oxygen sensor voltage. You can see the voltage change while the engine is running.

Make sure that the scan tool you get is Canbus compatible for the newer cars. I bought a canbus upgrade for the CP9145. It cost $50.00, but it saved me from buying a completely new unit.

I use the OTC/SPX 3049 scanner as a portable unit. When doing full-blown diagnostics, I rely on my AutoTap scanner connected to my lap-top computer.


I would inquire whether the code reader reads manufacturer specific codes or just generic global OBDII codes. If you are looking for cheap, dont be surprised when that code reader gives you a general code and says “Manufacturer Specific Code” You’ll just end up taking it to someone that has the capability to read them. You get what you pay for.


I bought a Cen-Tech CAN OBD II code reader on sale from Harbor Freight for $50 plus tax a few months ago. Regular price is $70. It comes with a booklet with generic DTC definitions and a CD with mfr. specific codes; 7000 codes on the CD and I would guess that includes what is in the book. The code reader reads and can erase codes. I have not yet needed it but it seems like an inexpensive way to get going for home use.

You can save even more money by borrowing an OBD-II scanner from an auto parts store. It’s free. You just need to give them your credit card while you test your car in the parking lot. They will print out the trouble codes and help you decide what you need to resolve the problem. Just ask at the counter whether they have an OBD-II scanner that you can borrow. For very occasional use this is the most cost-effective solution.

If you just want a reader just to check code numbers then a basic unit is alright. If you want something to aid you in more detail of the trouble then something like the Innova 3120 or 3130 would be better. I own a 3130 and really like it.