Girlfriend got a 97 V6. and it backfires (really badly) and throws a code when you get on it.
I don't know to much about that engine, what is the compression ratio, and what is the recommended fuel type. She sticks 87 in it and I talked her in to trying 89, and it still backfired. hopefully I can get her to try 93. but I would just like a little more info. since I've never worked on this engine.
anything I should check?

 

change the spark plugs and wires. that should do it prob. atleast that is the first thing to do...

Run 87 fuel, the other wont help.