Autel MS300 Universal Code Reader Auto Emission Accessory

Last updated: March 13, 2022


We looked at the top Auto Emission System & Accessories and dug through the reviews from some of the most popular review sites. Through this analysis, we've determined the best Auto Emission System & Accessory you should buy.

Product Details

In our analysis of 10 expert reviews, the Autel MS300 Universal Code Reader Auto Emission Accessory placed 7th when we looked at the top 7 products in the category. For the full ranking, see below.

From The Manufacturer

TURN OFF CHECK ENGINE LIGHT: MS300 check engine code reader can read, clear generic, manufacturer-specific and pending codes. It enables you to figure out why CEL is on like a pro and turn off check engine light instantly after proper repair. MECHANIC APPROVED: MS300 OBD2 scanner works with most OBDII compliant(OBD2 protocols: KWP2000, ISO2000, ISO9141, J1850 VPW, J1850 PWM, and CAN) sedans, SUVs and light trucks post-1996 for US cars, post-2000 for EU-based and Asian cars. DIAGNOSE IN SECONDS: MS300 auto code reader features easy to use 2 button design to read, clear DTCs to help home mechanics locate car problems fast. With an intuitive interface and easy-to-read backlit screen, this diagnostic code reader is easy to use. SMOG CHECK: MS300 car code reader retrieves I/M Readiness status to check emission-related systems like misfire monitor, fuel system monitor, comprehensive components monitor, O2 sensors, EVAP to help your vehicle ready pass the annual smog check. NO BATTERY NEEDED: MS300 OBDII scan tool communicates with vehicles through standard 16-PIN OBD2 cable and it’s powered by vehicle directly- no battery needed. Please follow the correct usage order: Engine off- Plug MS300 in- Turn Ignition On. RETRIEVE VIN NUMBER: MS300 engine code readers can retrieve VIN (Vehicle Identification Number) on 2002 and newer vehicles supporting Mode 9 for quick vehicle identification and cut time spent locating the cause why the check engine light is on. Retrieves generic and manufacturer specific Diagnostic Trouble Codes (DTC), includes definitions lookup software on CD and displays DTC definitions on screen.

Expert Reviews


What reviewers liked

The scanner works to diagnose in seconds. It's straightforward and easy to use, and you don't even have to charge it because it's powered by the vehicle directly. Although small, the unit is quite powerful and able to give emission-related information, and also read and clear diagnostic trouble codes.
A handy and easy to use device. The product is lightweight. Covers a huge range of vehicle. Hallmark of a capable scan tool. A compliant scan tool. It is affordable.
Comes with I/M Readiness function. Compatible with all OBDII-Compliant vehicles post-1996 in the U.S. Clears code and turns off check engine light.
No hassle to use the device. Show trouble codes within the shortest possible time. Durable computer plugs for OBD2 scanner.

What reviewers didn't like

Keep in mind that the unit might be unsuitable for some vehicle models. It seems that it fails to give accurate readings on some newer cars. Also, several users have complained about the screen being difficult to use. The buttons and the screen are small and make navigating through the menu a little tricky.
No built-in power supply. No software update.
Corded operation. Some reviewers accidentally deleted codes using this scanner. Lacks the features of pricier units.
Too small in size.
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