As title says the car does not hold idle after putting in a new battery (Red Optima). Do I have to reset the ECU? I have an 04 with 52,000 miles. Spark plugs, wires, and coils were changed at 40,000 miles. Any help is appreciated.

 

By putting in a new battery, you pretty much did an ECU reset. When you disconnected the old battery for more than a few minutes, it reset.

Car is re-learning the fuel trims so it might take a few drive cycles to settle down.
Don't freak out too much, give it a few drive cycles and then let us know if that doesn't cure it.

 

Thanks for your quick reply! I am going right now to drive the car for a bit and I will let you know.

 

Drive cycles = driving the car, shutting it off, and then driving again.......a few times.

Oh..................and DON'T shut it off cold!!!!!

 

Everything worked fine! I drove the car around for a while. I did 3-4 drive cycles and the car seems now to be fine! Thanks a lot for your valuable input!

 

You're Welcome.
Glad that was it....although I was 98% sure, it could have been something else.