Sounds like an ignition problem. The backfiring is probably from the plugs misfiring or you didn't get the plug wires back in the correct spots on the ignition block. Did you replace the coil/ignition block? check the wires that go to the block or take it off completely and take it to an auto parts store. they can test it for you and tell you if you need to replace it.
Wait a minute, I have the same problem and I changed the spark plug wires and the MAF sensor and the O2 sensors. I am now going to the crank sensor, then I am selling my car.
I had the same problem with my 98 Bonneville 3.8L I replaced pluggs, wires, and coil packs. It turned out to be bad fuel injectors at least 2, however I decided to do all 6. I found remanufactured ones on the Internet at very good prices all 6 under $200.
Check water level if you are losing coolant it is most likely a bad intake gasket either upper, lower or maybe both.
I have a 1995 Bonneville and at one time it sounded like it was backfiring also, but found out later that it wasn't. The problem was actually in the transmission and it only sounded like it was backfiring. I ended up having to replace the transmission.
Do mother birds really abandon their chicks if a human touches them?
Are Danny Devito and Joe Devito related?
Mrs Smith has nine children half of them are girls . how can this be true?
What is the Answer to rebus puzzle 1 knows?
Many southern states try to block school segregation by?
What is knee light light?
What times what equals 7?
Which alphabet letter is a part of a face?
What's the "Bastille" in Bastille Day?
If you could make one change to the education system, what would it be?
Is it safe to take a shower during a thunderstorm?
Why is the clock tower in London called Big Ben?
Why don't satellites crash into earth?
Where is the origin of the Panama hat?
Have you ever crashed a wedding or had your wedding crashed, if so what happened?
How many times did Joe Biden run for president?
What is the summary of the poem kitchen by taufiq rafat?
Is management an instinct or a set of skills and techniques that can be taught?
What is the characters of The Mulberry Tree and the Children by Sim Hun?
How many carbon atoms are represented by the model below?
BA-4 Why must a personal water craft operator follow U.S. Coast Guard rules and regulations?