This Cheap Harbor Freight Gadgets Turns Your Phone Into An OBDII Code Reader
It's never a good time when one or more dashboard lights decide to turn on. While some dashboard lights are more common and easier to explain, others require a bit more insight to figure out what's going on beneath the surface. This is done with a designated code reader, or with a phone and a budget-friendly attachment like the unit available at Harbor Freight. The MRBT smart mobile device OBD2 code reader from Maddox plugs into a vehicle's diagnostics port and utilizes Bluetooth technology to communicate with one's mobile device. Through the Repair Solutions 2 app, it tells you which codes are being thrown behind the illuminated dash lights.
In addition to this, the app has access to technical service bulletins, recalls, and OEM campaigns, The unit is compatible with vehicle model years between 1996 and the present day, and can collect and graph live vehicle data, among other features. The aforementioned Repair Solutions 2 app can be downloaded on both Apple and Android mobile devices. Also, this device retails at Harbor Freight for $54.99, which is significantly cheaper than most other code readers available through the store.
At the time of publication, there aren't any Harbor Freight reviews to speak of for this unit — good, bad, or otherwise — nor are there many floating around elsewhere online. But if the lack of user opinion has you turning away, you can at least look to other Maddox offerings for guidance on the brand's quality, or a code-reading alternative.
What the wider Maddox line has to offer
Reviews for the Maddox MRBT code reader are few and far between. YouTuber Fresh Vintage is a rare example, explaining that the OBD2 dongle isn't all that impressive on its own, but the app that runs with it has a lot to offer once vehicle data is collected. They found it to provide a lot of crucial information that casual drivers and home mechanics alike can benefit from.
If you want to know what you could be in for, or explore other options, Maddox's other code reader models have generated far more discussion.
A popular choice is the MR16 advanced 4.3-inch screen OBD2 reader, which is significantly pricier at $249.99 but has overwhelmingly positive reviews. Customers commonly praise the ease of use, the bevy of features included, and the appeal it has for more casual users. The much cheaper $44.99 MR5 1.8-inch screen OBD2 reader has also been widely praised on similar fronts. Multiple purchasers were happy with how simple setup and use were, as well as all of the information it could provide upon giving one's vehicle a read.
While the Maddox brand seems to score well with customers, at the end of the day, the MRBT code reader hasn't seen wide review up to this point. After all, it is one of the 2026 non-power tool additions to Harbor Freight's catalogue. Whether you feel it's something worth trying, and is suitable for your budget, is something only you can decide.