26,000 miles on a new cat without the cause of the cat failure being fixed can plug the cat. Depends on how much oil flows through it.

 

Tune up, (plugs, wires, cap, rotor,) timing chain and gears, (double roller please) plenum gasket.... couple different choices for which way to go there. Route wires per the TSB that can be found in the faq section.... If you are over 80K miles, replace front O2 sensor as well. I would test the cat too..... if the plenum is indeed blown (likely), cat is probably on it's way out as well.

 

Well i just did the tune up only month old ill start by redoin the wires like in the faqs an if that wont do it ill move on an do the keg