ecause he stated that his listings were at the very top for several years

He never said he was entitled to it, but because of his account status and achievements eBay rewarded him by placing his listings at the top. We're all familiar to that. Think about it, if your sales drop significantly in a short period of time, you would panic too. Now once you realize the reason of the dramatic decrease of your sales is due to eBay's decision to place your listings at the very bottom of its respected category then you would cal eBay too for help. This is a life changing experience. Its impact could hurt a business so bad that eventuality the business will destroy and disappear. I can speak of it because I am currently going through this depressing phase. Our business went from 1800 transactions per month down to 600 transactions. All because of some rare magical incident which has caused each and every of my listings to take a nose down dip to the bottom of the page, and no employee, supervisor, manager, account specialist, and tech support rep has a valid explanation.Rick go to the search bar and type Mercedes dia and stop at that point and look at the suggestions.  you will see eBay does not reccommend the words code reader, They recommend tool. Code reader are dead keywords for this item.  The reason is because it is far to specific versus the word tool, which will bring back a larger subset for a buyer to filter through with the left side bar options, which are cultivated from a few diffrerent sources including your item specifics.

You also have to look at the category they are suggesting.  You have it correct for this item, but many do not, and if there are more than one suggested categpry, then you should consider paying for 2nd category.  I am not saying you should automatically buy it but certainly you should consider it.

These suggestions are what eBay would like you to use for your keywords in the title, item specifics, and also in your description.  These suggestions are the path that ebay is directing buyers to so it helps quite a bit to be optimized to these suggestions.  By doing these things you will also do much better with external search engines.  A lot of traffic can be harvested from google, yahoo, bing if you are optimized correctly.

It is OK to use Code reader in the description and perhaps even the item speciifcs.  I think you should try to add a few item specifics also for this item.  The more Item specifics you can use the more refined search filters you will show in.  It is about getting your item in as broad a range of search results as possible.