I have a 1998 pontiac bonneville which i bought last week and when i bought it it was thought that i needed a tune up but when i tuned it up it acted worst i only changed plugs and wires i replaced all the sensors connected to the throttle body i cleaned the throttle body i replaced my air filter and i am stumped as to what it is can someone wit this problem hit me and tell me what they did to solve it

What are the cars symptons? I mean "it acted worse" can mean anything bro.

It'* the thing you didn't fix.

From the title and symptoms, that'* my honest best guess.

Recheck the wires make sure they are on tight and correctly. Make sure none are touching the O2 sensor wire. Test the coils. Clean the connections under the coils. Check the fuel pressure, change the fuel filter. Change the air filter. These are a few other things you can try. More info will help us.