document updated 15 years ago, on Dec 20, 2008

Options for reading check engine codes:

model	price (USD)	protocol	vehicles	based on
ELM320	$14	SAE J1850 PWM	Ford	PIC 12C5XX
ELM322	$14	SAE J1850 VPW	GM, Chrysler	PIC 12C5XX
ELM323	$14	ISO 9141-2, ISO 14230-4 KWP2000	Chrysler, European, and Asian	PIC 16C505
ELM327	$26	all of above, ISO 15765-4 CAN	all of the above	PIC 18F2x8x

various things that sell the ELM327 inside a kit or completed unit
- ElmScan 5, USB interface, $109 $130
- ElmScan 5, with ProScan software (screenshots), $130-150
  - Yeah, this is a really great package. All components are mature and widely-used, and it offers features that far surpass most "professional" OBD-II readers (that are 4x the price). And the "SALE NOW!" thing does make it even more compelling.However, archive.org makes it clear they have almost continuous "sales".
FULL KIT with nice PCB, OBDII connector, but DOESN'T SUPPORT CAN, $46
Cobb Tunning's AccessPort, $600+