Quote Originally Posted by Scottydoggs View Post
if you take the upper o2 out that will let it leak enough to tell if the cat is clogged.

box wrench works for the rear o2. or open end, a line wrench would work as well.

needing a tune up can also make it fall on its face. floor it and nothing happens but some sputtering and bogging.

clogged cat kinda sounds like a vacuum cleaner with a full bag when you floor it.
Changed the oil and it wasn't really smelling of gas, black and combustion smell, to be expected. I took off the front O2 sensor and it works! Not one hundred percent of course but the gas is still trying to get out of a small hole. So the cat is blocked for sure. I'm now wondering if the slight oil consumption I've noticed over the last few years and brown coolant (had to flush it a while back) is due to a manifold gasket leak. Getting oil in water and into chamber and that has blocked up the cat with contaminated exhaust gases and maybe ruined the sensor which has then contributed to the problem? Thoughts?
I plan on fitting in a generic type cat and clamping it in to the existing pipe work, just for ease of fitting if not cost saving. Do these seal OK?