If the check engine light is on, get a code reader. I just found out Calif parts stores do not do free code reads anymore, least they said so. Also AAMCO shops are hit and miss whether they do free reads, I guess it is fair.
So by yourself a reader. Autozone has a sale going on at least in my area where their code reader that normally sells for $130+ is now selling for $99. It IS an OBD II and CANBUS reader. Be sure whatever reader you buy is CANBUS capable, not all OBDII readers also read CANBUS. There is a nicer model($200++) that is supposed to give graphic readouts but that is possibly more than I really need. My car has only flashed the check engine light on 3 different occasions in the 6 years I have owned the car and all those occasions were bad coils or spark plugs so a simple missfire message and which cylinder it is, is all I need. But, the mid range model I got does have real time monitoring and displays all the parameters that are monitored for the Calif Smog test, so good enough.
Note, I had an older Omni OBDII reader that would talk to the LS but it could not read most of the codes since it was NOT CANBUS capable, so maybe whatever reader your are using now does not read Canbus, about half the ones I saw would not read CANBUS.
I forget what brand the reader I bought is, but it is bright orange/yellowish in color and the size of a pack of cigarettes and has a multiple line LCD display, besides they are all made in China. The manual is rudimentary but the chacter display is fairly complete and the results on the display are usually self explanatory.
Mine read Ignition misfire on cylinders 2 and 4 and another two messages said something like Ignition circuit B and F failing. I assume the first message is just a generic spark misfire while the second message tells you it is probably the coil. I changed the two coils(yes I know you should change them all, but I am getting faster at this now) and the car runs great again. Cost per coil is something like $44. I am also interested in seeing whether the common wisdom of changing all the coils at the same time has merit or is just a better alternative if you are forced to have someone else do it thus having to pay for all the work when only some really needs to be done. I will see how it goes, If I was to prdict the next coil failure I would guess when the weather gets back into the 90s this summer.
Note that there is a reward club card at Autozone which if you get 5 DIFFERENT transactions over $20, you get 1 point. 5 points means $20 on your account. So now I have 4 points, 1 for reader, 1 for coil, +1 for another coil at a different store(they were out) and 1 for a lens cleaner kit.
So anyway, I plan to use my code reader for the usual, but expect only coil failures on the remaining 6 coils I did not replace. I currently have about 128K miles and replaced plugs at about 116K.
At $100 a code reader will pay for itself with one use. If you know what you are doing.
Jim Henderson
