Hey guys,

So, sporadically, the car sends a cylinder one miss-fire code. What is this and how do you attempt to fix it? The car runs fine, but it pops up fine, and then runs off until you flash it. Should I check the plug, replace the coil-pack? any suggestions?

Thanks!

 

Yup,
Id check the spark plug first....
Clean Re-gap... Might be a good idea to do all of them...

If that doesnt help swap #1 and #4 spark plugs
If the problem moves to #4 cylinder, you have a bad plug, id advise then
to replace all 4, or you cuold just swap out all 4.
If that doesnt help swap the #1 and #4 coil packs... then see
if you get #4 cylinder misfire... if you do its in the coil pack
if not, its something ealse....

Id Ohm check the wires from the coil pack to the PCM
While it oculd be some what of a pain, wireing it itself isnt that expensive...
If the ignition side is good, then you could have a valve train issue.. thats where it
gets pricy.

 

a clogged injector can cause a misfire, too. you won't get enough fuel into the cylinder, and then you misfire. Tho not as likely as an ignition problem, it is more likely to be, in order, spark plug -> coil pack -> igition wiring -> injector -> valvetrain.

Do as insylem suggested, it is a great and easy method to diagnose spark plugs or coil packs. you can go for the spark plug diagnoses first if the plugs have been in for a while, so you can check their condition, if they are relatively new i'd swap the coil packs first since they are on top. unbolt coil pack for cylinder #1 and #2, swap, plug back in, drive and see if the code changes. if it stays in cylinder one, then the plug or wiring is to blame and not the coil pack. swap plugs as they suggested, replicate problem, see what changed it.

If you cannot find the issue when diagnosing the ignition system properly, i'd look into a clogged injector before you look into any valvetrain issues, because it is cheaper to diagnose and replacce an injector then it is to diagnose and replace a valvetrain related issue.

if you have access to an obd-II reader with DTC resetting capabilities, then that's great, if not then just unplug the battery + AND - at the battery and touch together for 1 minute to wipe out any codes (also wipes out learned short term and long term fuel trims as well as shift adapts and any other learned driving characteristics.) do this if necessary so you can avoid having to go to autozone for a free scan every time you want to diagnose the problem

 

Yeah, I was just gonna go to Advance and reset it.. It's just right up the road..

I will likely be finishing my s/c piece together over summer, so it'll get newcinjectors anyway.. And the plugs only have about 15k on them.. Replaces them at 50k with new Iridums.. And I run one of those system cleaners once a month.. And it's always gotten 93..

But yeah, every once in a while, at idle, it kinda bogs down for a second, then balances out.. Drives well otherwise though.. Think that's an injector?

Thanks for the info!!