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2017 idle felt a bit lumpy on startup today so I hooked up my Thinkcar OBD scanner and checked to see if there were any misfirings. Got a few “emission relevant” misfirings of all cylinders. Not sure how that’s different from catalyst damaging ones. I’m thinking maybe it’s time to replace spark plugs/coils. What y’all think?
Not familiar with that jargon, did it have a pending code for an event? P0300 or freeze frame data present? I would definitely make sure battery condition is good and fresh fuel. If it's not driven much I'd recommend a few daily hot laps before proceeding.
I would check out those O2/Lambda sensors first...a lot less spendy and could generate similar results.
Will check them out. Thanks.
Originally Posted by EJ_Rapide
How many miles on the car? When were the coils and plugs last replaced?
12,500 miles. Still on original spark plugs and coils.
Originally Posted by J doubleU
Not familiar with that jargon, did it have a pending code for an event? P0300 or freeze frame data present? I would definitely make sure battery condition is good and fresh fuel. If it's not driven much I'd recommend a few daily hot laps before proceeding.
There were no warnings or codes, I hooked up the obd scanner just because the idle didn’t feel smooth. I just put a new battery in last month and it sits on a battery tender whenever it’s parked for more than a few days. Whenever I drive it, a few times a month, I make sure to kiss the red line at least once when it’s all warmed up.
I agree with J DoubleU, An Italian tune up wouldn't hurt!
Additionally, when was the last time you had the air filters replaced? Insufficient air flow, and bad O2 sensors, or either independently, could cause a rough idle and emission codes. Alternatively, a dirty mass airflow sensor can cause that. I would not immediately go to plugs/coils in this instance because ALL cylinders are having a misfire, indicating to me that it some component that is informing the coils when to ignite the plugs, i.e. another emissions related component like 02 sensors, MAF, et al. are not within spec.
Is your misfire correction procedure coast down procedure completed? If the battery has been disconnected, you may need to re-do that to ensure things are up to spec before diagnosing hardware. Just my thoughts, best of luck.
