Trying to remove cat urine odor is a very difficult proposition and 
one of the worst things for your carpet. You may have to call a carpet cleaner if the cat urine in the carpet is quite extensive. Small cat urine problems may be handled by the resident if properly treated. The following steps should help to ensure the cat urine problem is handled in the correct manner.
The subfloor is often affected when cat urine is present in the carpet. When cat urine dries it will form crystals that are almost impossible to remove through the backing of the carpet. There are a variety of products on the market that are specifically designed to deal with pet urine. Normal household cleaners and even standard carpet cleaners will not be able to clean urine out of carpet. Do not be fooled by products that claim to remove cat urine odors from carpet. Many of these products use very heavy fragrances to simply cover the odors for a short period of time.
The urine in your carpet will continue to off-gas odor as they slowly decompose over time. In addition, the crystals are providing a breeding ground for bacteria which will produce waste and make the odor even worse.
It may be an inconvenience, however, the products used to eliminate cat urine usually require at least two days to do their job. The enzymes cannot be rushed and need adequate time to ingest all of the urine crystals to completely remove the odors. The worst thing you can do is to apply the product for a short time and then put a fan on the area to speed up the drying process. The easiest way to ensure the product will have time to work is to cover the treated spots with plastic for a couple of days while the product works.
Do not be embarrassed to have company over because of serious odors in your home. By applying cat urine odor removal by the proper method you can be confident in your success rate.