I have an 89 4.2 5spd. I am in the process of replacing the front pipe. You can still get an upstream tube from RockAuto.Com if you need one. It connects from the front pipe to the check valve. You can't get a downstream tube as yet, and I searched. Possibly in a few months they will be available. If your tube to the Cat is in good condition you can get the emissions kit to connect it just about anywhere; it comes with a metal tube, hoses and clamps. Your front pipe should have an opening (connection)(nipple) for the tube at the top where the front pipe connects into the exhaust manifold. If your current front pipe doesn't have it just replace it with a new aftermarket OEM fit front pipe. It will have the opening for the tube and the tube just slides on. You can get a 3/4" Dorman emissions clamp from O'Reilly auto parts to connect the tube to the front pipe. Much better than trying to use a universal clamp which won't provide enough pressure. If you need to connect the end of the tube to the check valve and the valve is corroded where it won't separate you can get one from Morris 4x4. Once you go into the emissions section for "CJ's" it will list the part as also fitting YJ's. It's a bit expensive but if you need it you can get it. Hope this helps.