Spark plug OEM Toyota or OEM Subaru

Unfortunately no--replace them. The electrodes wear down and become less efficient. The good news is that iridium plugs have a tremendous lifespan. You're supposed to change them every 100k miles/167k km.

Changing my sparkplugs for the first time (32k miles, yes it's early but I got a great deal on the plugs) and found that the stock plug in cylinder 4 actually had a ground electrode defect and was significantly thicker than normal. The car runs stronger than it ever has as this was likely causing extra timing pull.

O drove my Corolla to the point the spark plugs weren't firing and the car wouldn't start. I changed the plugs and it ran great after that.

im at 95k with the original plugs. no issues

I waited till like 100k to do my spark plugs on my 2013 Crosstrek, they were still good just not as efficient

Just traded in my 2015 Forester with 219,000 miles and the original spark plugs.

Maintenance: 39th Oil Change (every 10K) and Tire Rotation, 13th Engine Air Filter, 13th Cabin Air Filter, 3 brake jobs, 3 coolant flushes, 2 spark plug changes w/carbon cleaning, no suspension work, no transmission service, 1 Break Down at 280K Due to a Design Flaw In The MGR Cable Which Powers The Hybrid System $5200, cat issue at 380K due to bad gas, no hybrid battery replacements in case you were wondering, does not consume oil

We just got the 60k service done (spark plugs) and it still does it.

I was given an "offer" to have my spark plugs changed for $368!

a spark plug job on an STI can be a 6+ hour job :thumbdown: