a few 87 Nissan Pulsar NX questions.....please help! :(

Your second problem might be a clogged cat converter. My 85 Pulsar behaved the same and it will only get worse. If the exhaust gas can't get out of the cylinders, the gas/air has a problem getting in thereby losing power. Secondly, there is a great deal of back pressure created in the engine which causes blow-by of the rings and valves causing burning of the valves and other major problems, and that may be the source of the tapping noise you hear. My 85 had two converters, one in the exhaust pipe under the driver's seat and the second in a cast iron housing attached to the bottom of the exhaust manifold. I narrowed it down to the cast iron one by removing the exhaust pipe from the front of the exhaust pipe cat and running it with the pipe disconnected. There was no improvement. When I disconnected the cast iron one from the manifold, it ran fine. You have two remedies. Buy a new cat, or just gut it. I took the second option. Caution: Your car probably won't pass an emissions test without both cats. I didn't have to worry about that since an emission test was not part of my annual inspection

thanks a bunch guys! i'll check out both routes & see which one goes closest to solving the problems.

really appreciate it, Reggie