I don't know what the emissions laws are like in the Philippines but hollowing out the trap ox/ox cat may be the simplest solution. It will not be as good as a pipe replacing the trap ox but you will get better performance than you would leaving it intact.

If you do hollow it out, make sure to get all the stuff out. If you don't it can break off and damage the turbo.

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green 85 300SD 200K miles "Das Schlepper Frog" With a OM603 TBO360 turbo ( To be intercooled someday )( Kalifornistani emissons )
white 79 300SD 200K'ish miles "Farfegnugen" (RIP - cracked crank)
desert storm primer 63 T-bird "The Undead" (long term hibernation)

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