7sisters

I've experienced a similar situation with model and year after driving it for 100K and 10yrs. Recent, fuel filter, tune up, good things, although still symptomatic. The experience could be the catalysts which I've researched to either over heat/quick temperature change, are damaged, or O2 sensor replaced/MAF cleaned (then throtle and each connection, make worse?) The check engine light is out thus no codes until flashes seen, (never seen any of that in driving) test similar to emissions, or replace them with used that supposedly can be checked as good and look inside current catalytic converters after change to see if MAF/O2 cause. May not practice what I believe although I do care about the earths atmosphere. Simply like to see if back pressure is created and keep traffic happy although santas elves are busy/shops owners need to put priority to those with more money. Thank you all for any feedback...