I've been wanting to preserve some bbq sauce that I make so I decided to can it in glass jars with the hot water bath method. My question is, should I be adding citric acid ? Or does the lemon juice I use in the recipe take care of that ?

the lemon juice should be fine

For canning Barbecue Sauce use the following techniques:
Canning using hot pack method with 1/2” of headspace.
Processing with a Water Bath for 30 minutes at 212 degrees.
For elevations above 1,000 foot level see Altitude Time Adjustments.
After processing, remove from boiling water and place the jars on a towel, separated by
1” to cool naturally as quickly as possible.

if using fresh tomates for your bbq sauce - use 5% vinegar (white or apple)

Thanks Mama, I was hoping the lemon juice took care of that, because I only had that thought after I had canned up a batch :o