Hi... I have a 2003 TL Type S and i got my EGR ports cleaned out last year.. and since then my car has been running rough and seems like its worse now... my issue is rough idle,hesitation,bucking and lack of power.. so far I'd replaced the o2 sensor, MAF,EGR valve, Coilpacks/sparkplugs, throttlebody/IACV, Upper intake gasket,checked the catalytic tried Redline stuff no luck and always used shell 91oct.... although i didnt try seafoaming the engine.... i just wanted to know if i still have to replace the sparkplugs after the seafoam has been done... probably the plugs have 20,000kmz on them.....btw no CEL