idk whats wrong with my car,i was told i needed a tune up because the car was running bad,while the car is running the engine shakes and the check engine light blinks i got a tune a tune up today i changed all 6 wires and all 6 spark plugs and all 3 ignition coils i started the car up thinking it would run better,but it still runs the same rough at idle engine shaking and the darn check engine light is still blinking,anyone have an idea what the heck is goin on? anyone had this problem before if any of you guys did or can help please let me know,BTW the car is a 96 Lumina with a 3100 V6

 

If engine shakes then it may be due to the bad valve seat. If engine running rough at idle then its oxygen sensor rading lean. Change it.
1996 Chevrolet Lumina Oxygen Sensor - Standard Motor Products, Denso, Bosch - TheAutoPartsShop - TheAutoPartsShop

 

Sounds like an injector to me. That would be a code 3XX the X being which cylinder or multiple. There is a youtube vidio showing a simple fix, basically take (with it running) an extension, with a hammer and tap gently on the injector, that should work. Again, the 3xx code will tell you which cylinder(s).