I removed a section of wall not to long ago and did have to rewire some but everything was put back together and has been working for a couple months. The other day it seemed like the breaker popped except there were things on that circuit that were still working? I tested all the outlets with a tester and it says they are hot but when something is plugged in it doesnt work. For example the tv was plugged into one of these outlets and works fine when plugged in to another outlet but not to the original. When plugged into the original outlet the cord is "hot" according to the tester but still the tv doesnt work, what is going on?!!!!
Like @Petey said you need a different kind of tester, and one of those plug-in testers with the 3 lights is great for receptacles. Assuming all is properly grounded the tester is capable of indicating an open neutral. I would first confirm that an open neutral condition exist before you go any farther, and then understand that the problem (the bad connection) could actually be at a lighting fixture, switch or any box that this circuit passes through.
A loose neutral connection can even be in the breaker panel, in which case the entire circuit would be malfunctioning. The other possibility, that can throw you, is that the bad connection can be in a box where the receptacle tests good or the light works, but it's not sending the neutral downstream from there. Otherwise you're likely to find the problem in one of the receptacle boxes that isn't working, and my guess would be it's going to be in one of the boxes that was recently installed or worked on.
If you want to get into this, determine which boxes you think you should look in and start with the most upstream one (closest to the circuit breaker) and work (search) downstream. Turn off the breaker for the circuit, and after you take the plate cover or the lighting fixture off probe with your voltage sensor to be sure you're off. After you pull out the device to get a look in the box, probe with your sensor again , especially if there're more wires in the back of the box.
What you're looking for is a wire on a loose screw, a bad stab connection or, more likely, 2 or more wires in a wirenut and one is loose. Examine everything in each box. Tug on the wires, especially wires in wirenuts and stab connections. If you find a bad stab connection, remove the wire from the stab, put a hook on it and put in on an associated screw. If the screw(s) is already occupied (never put more than 1 wire on a screw) either pigtail the wires so that only 1 wire needs to be on the screw or replace the device and use the stab on the new device.
If you're lucky you'll find something loose with no harm done, but you may find some wire damaged due to overheating, especially if you were using the circuit with a high electrical load, anything that heats, cools or has a large motor, in which case the repair will be a little more involved.
Otherwise, I don't know where you're at, but I live in the Phila suburbs and I have been known to work for beer.
You are not using a "tester". You are using a voltage sensor. Big difference. You are getting a voltage reading but it's not working? This is almost certainly an open neutral on this circuit. A circuit needs both hot and neutral to work. Get yourself a real tester and test from hot to neutral and hot to ground anywhere possible. Find the open neutral and you'll find your problem.
My real advice is to call an electrician. This would be the safest bet.
I agree with Rand and Petey. The plug-in receptacle testers are great for determining what your exact issue is, especially as a novice, but a cheap digital multi-meter ($25) is more useful overall. You can also get just the plug tester for $8 or a combo-pack that includes the voltage detector you already have for $30, all at Lowes. They have a new line of electrical tools that I'm very impressed with. I'm a commercial electrician and I've been replacing my tools when needed with the Southwire brand stuff at Lowes.
I'm in the Seattle area and I'd be willing to help out in-person if you need somebody. I quit drinking because I was a home brewer myself and over-did it, but I'm willing to barter or do a little work for much less than it would cost you to hire a contractor if that's what you're looking for.
Good luck and keep us posted.