About ten seconds of internet research would have shown you that carbon-14 dating is only done on dead things, so no, it isn't true.
When used inappropriately -- as is the case for every single one of the creationists' "examples" of dating methods being "wrong" -- any test of any sort can give bogus answers.
Try measuring your body temperature with a fever thermometer held by a red-hot pair of pliers, for example. No one in their right mind would expect that to produce a correct reading, nor would they blame the thermometer or denounce it as "inaccurate" or claim to have "proven" that it can't give a proper reading when used correctly.
But that's exactly the kind of dishonesty the creationists try to pull when they put out propaganda trying to "disprove" dating methods by giving examples of "wrong" results obtained by applying dating methods in inappropriate circumstances which no competent scientist who wanted to get an *accurate* reading would ever do.
Regardless of their ability to wave around a few examples of inappropriate answers achieved by applying dating methods inappropriately, the creationists fail to deal with the core question: If dating methods are actually unreliable, how is it that (when used appropriately) they a) produce correct dates for samples of known age, and b) produce dates for a given sample that match the results of dozens of other dating methods which are based on different methods and different physical processes? If any of them were "wrong" or based on incorrect "assumption" about the underlying physical processes being used to gauge the age of the sample, why do all the different dating methods produce the *same* results for a given sample? If they were wrong wouldn't they be wrong in *different* ways and different amounts?
See for example:
Radiometeric Dating Does Work!Are Radioactive Dating Methods Consistent With Each Other?
Radiometric Dating: A Christian Perspective
Radiometric Dating and the Geological Time Scale
Breakthrough Made in Dating of the Geological Record
Formation of the Hawaiian Islands
How Old is the Earth: A Response to “Scientific” Creationism
Other than isolated samples which give funny results the only things that routinely date too old are shellfish. Because marine shellfish live in the ocean, and because some of the carbon they absorb is from deep water environments (where it has been out of contact with the atmosphere for a long time), they usually give dates which are several hundred years too old. This is something that has been well studied. The standard reference for the correction factors for various parts of the world are given at: Marine Reservoir Correction Database.