Advance Auto Parts has the Actron CP9125 Pocket Scan Code Reader for $50 + $1 filler - $20 off with coupon code A123 = $31 with free in store pickup or $9 shipping. Enables reading of OBD II diagnostic trouble codes for 1996 and newer cars. Good Amazon reviews.
Well, yes you have mastered BenMath 101, #1, $46 on Amazon is indeed lower cost than $31 from Advance Auto Parts.
However, BenMath course 201 would've taught you that the same one you linked is also available at Advance Auto for $41 + $9 filler item - $20 off code A123 = $30. Even if you have to pay $9 shipping instead of free in-store pickup, ($39 for the scanner AND 9 bucks worth of more stuff) < $46.
#2 - Sorry for assuming the info you learned in 201 (did you pass?) was patently obvious... I guess I should have done the extra bit of work for you and pasted the link to the same device at Advance so you could have reached the same conclusion a bit faster.
This next-stebaconp code reader is actually being sold for a few dollars less:
http://www.amazon.com/Actron-CP9410-PocketScan-Diagnostic-Vehicles/dp/B000YIW5VA/ref=pd_sbs_auto_2
Well, yes you have mastered BenMath 101, #1, $46 on Amazon is indeed lower cost than $31 from Advance Auto Parts.
However, BenMath course 201 would've taught you that the same one you linked is also available at Advance Auto for $41 + $9 filler item - $20 off code A123 = $30. Even if you have to pay $9 shipping instead of free in-store pickup, ($39 for the scanner AND 9 bucks worth of more stuff) < $46.
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_OBD2-PocketScan-Plus-Actron_9090012-P_N3389_T|aconbay
Some vehicles will display engine codes on the dash cluster. No need for a code reader.
#3 Usually those made before 1995.
#2 - Sorry for assuming the info you learned in 201 (did you pass?) was patently obvious... I guess I should have done the extra bit of work for you and pasted the link to the same device at Advance so you could have reached the same conclusion a bit faster.
No it's ok, sometimes we need to be told $46 is less than $31 because it isn't obvious.