HELP! Can i stop a leaky PVC pipe joint?

Just installed a tub drain. The joints are all fine except the last one where to line enters my main house 3" pipe. The reducing Y fitting i used there is leaking about one drop per 5 mins of shower running on the downstream side of the joint. Is there an easy fix? Repair? Weld?
HELP!!!!!!
Thanks

Sounds like you either didn't properly solvent weld the hub correctly or you ran water into this piping too soon. You will have to cut out the fitting and do it over again to make it a permanent connection. Band aiding the situation will lead to the connection leaking in the slow erosion of the solvent weld joint.

Nope, no easy fix. As you may know, PVC "glue" actually is a solvent that melts the surface of both the fitting and pipe and essentially welds the pieces together. Apparently you did not get good coverage with the solvent and so the joint is leaking. There is no way to dab it with more solvent or epoxy, and there is no tape that will provide a lasting repair, no matter what the advertising says, it can't be depended on. The best way to repair the joint is to cut it out, and install new pieces. To make the final connection, you may need to use a Fernco slip connector that clamps on both pipes. I believe plumber may have some tools that they can use to remove bad fittings, and while this would obviously be somewhat costly, it might be the best way to go in the long run.

Hmmm, was told by an experienced relative that since it was not "under pressure" (it is a drain line), that i could clean it up real good and use either epoxy or maybe even PVC cement. Not true???

Even on a line not under pressure, there is no reliable sealant which can be installled on the outside of the pipe. This fitting needs to last unseen for 25+ years.

There is not easy repair for this. The best you can hope for is to cut away the trap arm a few inches from the stack and then try to wiggle the stub out of the hub leading to the stack. Sometimes you don't get enough into the hub and that causes a leak. If you are lucky the weld did not take and you can just work it out and then sand down the hub a bit to get it smooth again. If you are so lucky, just insert a new stub and attach to the remainder of the trap arm with a fernco or maybe you can solvent weld a coupling. If you are not so lucky, you can try cutting the trap arm flush withthe hub and cutting the reaminder of the arm with a hack saw blade in segments and then chisel away the pieces. This is not easy. If nothing else works, you will have to cut away the fitting in the stack and go from there. Good luck.