Article: Once you've installed a new catalytic converter, one thing you'll want to do immediately is double-check to make sure there aren't any leaks in the exhaust system on either side of it. Depending on where it is, an exhaust leak can cause a variety of problems for your vehicle, including reduced fuel efficiency and long-term damage. There are several ways to find an exhaust leak. One is to simply be observant while you drive if your car sounds louder than normal when it runs or seems to "rumble" more, you may have a leak. You can also check for leaks by jacking your car up, starting it in park, and carefully moving a lit candle along the length of the exhaust tubing. Leaks which are invisible to the eye should cause the flame to waver or blow out. One problem that can occur in faulty catalytic converters is that they can become "backed up" with soot, debris, and other exhaust byproducts or broken apart inside the converter. In this case, the engine's ability to rid itself of exhaust is hampered, which can cause a vehicle's fuel efficiency to plummet and can even cause the engine to stall in severe cases. Luckily, performing a backpressure test is simple just screw a pressure gauge into the oxygen sensor's hole before the converter in the exhaust manifold in most vehicles. The pressure reading should be less than 1.25 psi when the vehicle's engine is running at 2,000 RPMs. The worse the congestion is, the higher the pressure reading can be. Very bad backpressure readings can approach 3 psi. If your car's converter is old and worn, one simple test can tell whether it needs to be replaced very quickly. Simply grab a rubber mallet (or similar tool) and give the converter a firm hit. If you hear any sort of rattling, your converter needs to be replaced this indicates that the metallic catalyst within has begun to corrode and crumble. However, if you don't hear a rattle, this doesn't necessarily mean that your converter works well. There may still be other problems with it. To be clear, this test can only tell you if you have a bad converter, not if you have a good one. Catalytic converters can be tricky parts if you're in doubt about whether or not yours is functioning properly even after performing the tests above, don't hesitate to take it to a mechanic or specialist. These professionals will have access to the type of equipment that can be used to perform more advanced tests, like delta temperature tests, oxygen storage tests, and CO2 tests. Most auto shops that offer smog testing will be able to perform these sorts of emissions tests.
Question: What is a summary of what this article is about?
Check for exhaust leaks. Measure back-pressure in the exhaust system. Perform a mallet test for old converters. Consider more advanced tests.

Being able to reach treats immediately is important for training, so the dog learns which behavior is being rewarded. Traditionally, dogs are taught to walk on the left side, so keep the treats in a left pocket or waist pouch. Put a few small treats in your closed fist and walk along with your hand in front of the dog's nose. Every few seconds, pop a treat into your dog's mouth as you continue walking. If the dog runs forward or hangs back, stop and call the dog to you. Continue to call the dog back patiently, until it returns. When it does, tell it to sit, feed it a treat, and praise it. Continue your walk as before, feeding it treats as you do. If the dog starts walking ahead but hasn't lunged to the end of the leash yet, say "Easy." Say "Yes" and give a treat if it responds by turning around and coming back to you. If the dog pulls at the leash to eliminate or to sniff an object, stop and call it back. When it comes, praise it, say "Yes," and let it go where it wants to go. Follow it so the leash stays slack. When you start out, you might just walk up and down the block, so the dog doesn't stop paying attention. Each day, walk a little further. After at least a week of this, straighten up and keep your hand near your pocket of treats, around waist level. Every other step or so, take a treat from your pocket and lower it to the dog. If the dog can walk for several minutes without pulling on the leash, you can slowly increase the number of steps between treats. Try to reach one treat per minute within a couple weeks. Dogs have trouble understanding the purpose of punishment, which makes it an ineffective motivation technique. You should only use these techniques sparingly to discourage unusually bad behavior, not on every walk: Never use these techniques with a choke, pinch, or prong collar, or a head halter. If the dog ignores your commands to slow down and return to you, stop talking and turn back the way you came, tugging at the leash gently. Praise the dog when it catches up to you, then turn around and resume the walk.
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One-sentence summary --
Keep treats in a pouch or pocket. Feed the dog treats as you walk. Stop and call the dog if it moves away. Grant permission to investigate objects. Gradually increase the duration of the walks. Reduce the number of treats. Use punishment sparingly.