euphanom

Here are the specs: 1998 Civic LX D16Y7 with approx. 300k CEL IS ON.

CEL Code: P0420
I currently live in AZ where heat IS a problem. Although this car has NEVER overheated or ever run above normal temp.

Anyway, I've been having this problem when I come to a stop the car will stall. It will fire right back up no problems, but the idle is rough/lumpy, acceleration is normal, no hesitation. As I continue to drive, the car will go from stalling, to almost stalling, and then it will correct itself almost by magic, and it will idle perfectly.

I took it in for an oil change and they stated that my battery was leaking. I didn't think sealed batteries could leak, but anyway... I was wondering if this is just the battery's fault or something else? I don't see how the battery could cause this if it stars first time, every time.

Thanks in advance for any help/suggestions

Eric

Former User

P0420 generally means the cat is dead, but can also be caused by an exhaust leak.

The cat is killed when the engine runs rich, which is commonly caused by engine misfiring related to bad plugs, wires, cap, and rotor.

Your battery simply failed. Replace it if you have not already done so.