I have a wood burning fireplace that was used for many (20) years with no problem. Converted over to a gas log 5 years ago and have had a consistent gas type smell whenever it's in use. Not sure of the log type, but paid about $400 for it. The log has been used for many hours so whatever "new" smell may have once existed is long gone. Chimney is clear and damper is fully open. I turn the gas on and then close the glass doors for maybe 10 minutes to warm up the chimney and get a good upward draft going. Then open the doors and still get a gas type smell , regardless if the gas is turned fully on or turned down.
Wife is ready to get rid of it, but I don't want to spend a lot of money for a new one without understanding what is wrong with this one. Help!

I hope you have the wood to gas conversion done professionally and if so it is time to call them back.

There is much more to the conversion than just placing the fake gas logs into the fireplace and hooking up a gas line. Besides a professional chimney/firebox cleaning the unit needs to have the gas pressure checked and adjusted to prevent any CO from entering the home.

If you installed the unit then call for a professional to do the required install checks. If a company installed this unit call them back.

I recommend a CO detector properly installed on all open face fireplace conversions weather it has doors or not.