Hello everyone I'm Ivan from north Jersey with a 2002 s2k 161k. I want to change my ap1 retainers to ap2. So just going to do the exhaust and my question is do both upper and lower retainer get replaced or just uppers? My mechanic says just the upper and found it odd. Thanks
Ivan

 

The spring seats? Nah, leave em. Just do the retainer and new keepers. The spring seat is the same part number from 00-09, and is typically something that never gets replaced. But they're $3.50 a piece in case you feel like spending your lunch money on new ones (go get a nice steak...)

 

Thanks for the info. Appreciate it.

 

There's no benefit to doing the exhaust side -- in fact it's counterproductive. Do the intake retainers only:
https://www.s2ki.com/forums/s2000-un.../#post18658304