Wrong Plugs

[Kiotae]

So, even though the previous owned had the plugs changed only 15k ago, I decided to check them out while I was cleaning the throttle body. Low and behold, there were Denso PK16TT plugs in there, which are not dual ground.

Could this have caused any damage?

Yes, I'm replacing them before I drive it any more.

 

[kball]

Shouldn't cause any damage. Single ground plugs will just wear out faster.

 

[shootmymime]

i just changed mine out yesterday with NGK BKR5EKB-11. Stock number 3967 from oreillys. they are a bit more than what the dealer quoted because they are NGK. (dealer says denso) but i payed 4.49 a plug. these NGK are OE style and basically the same thing. dual ground copper innards. it took me about an hour to do all 6 FYI.
MAKE SURE YOU GAP THEM TO .43 (mine weren't gaped) AND GET SOME ANTI SEIZE GREASE FOR THE NEW PLUGS.

 

[Millerad1651]

Advanced auto has the NGK dual grounds for $3.29 each. Just bought some last week. No harm in the single ones, just aren't as good. The PO had just changed the plugs, so I never looked at them. Turns out they were single ground, and I had been running them for 22k miles without problems.

 

[Kiotae]

If they won't hurt anything I may just leave them in.

I have a limited amount of time to work on it during the winter and would rather spend the time dealing with some rear axle rust.

 

[gannonrt]

If they won't hurt anything I may just leave them in.

I have a limited amount of time to work on it during the winter and would rather spend the time dealing with some rear axle rust.

You'd be fine doing that. If you notice fewer miles per tank, decrease in power or some missing then its time to change them soon. Even then though you can still go at least another 3-4 tanks if it doesn't bother you.