Autel MS309 Universal OBD2 Scanner: Engine Fault Code Reader for Clearing Codes, Viewing Freeze Frame Data, and Completing I/M Readiness Smog Check Review

Sealed new packaging (some readers say not new). I've used it twice and it seems to work great. I've had issues with my car due to this cold weather and the commute to work, so it's handy to have and know if it can wait until I get home or if it's an emergency. Next time my light comes on I'll take it to a professional tester and compare the results. If I find inaccuracies I will add them. If there are no more reviews from my side, you can be sure that I'm lucky.

It couldn't be simpler. Received the device, quickly read the instructions. Popped it into my GMC and hit enter three times and code PO446 (exhaust emissions) came up. Considering I've seen this code before, when I asked the store to pull the code I knew it was related to a faulty gas cap or similar item. Although you can delete the codes by disconnecting the car battery, the device has a delete function. Just go back to the main menu and click on the items to go to option 2, Delete. Confirmed…

This is a very cheap item that saved me hundreds of unnecessary so-called mechanical repairs at the auto shop. This helped me pass the emissions test, which only scanned my car for possible problems, even though my car is fine. I cleared the codes and the runaways were gone in no time. The application is very simple and only takes two to three minutes. I also help my friends clean up checkbox codes, so Code Reader has already paid for itself many times over! That's a lot for a small price.

My 2004 Tahoe 5.3 liter gave me an error message and as I'm trying not to pay a high price to have my car shipped to the dealer I have I decided to order this device because of the cost and the simplicity. The price was reasonable and it was easy to use. As it turns out, I was able to find the problem area after receiving the code for my problem. In this case it was a defective electronic part on the exhaust pipe. I just removed this part and bought another from NAPA and it cost me less than…

Not for professionals or enthusiasts. Basically a first step tool to measure how engaged you are. The Autel AL301 has several unassigned codes that may appear as "B2aaa". This is a placeholder value (e.g. -9999), not real code. It should have been renamed as "N/A" or "Unknown" like its MS300 sister product. Many of these B2aaa appear in European vehicles when the CAN-BUS is not ready or reading out of sync. Disconnect, stop engine, reconnect, turn on battery, turn on engine, read again…