california civic hx

[thebrad]

I get the 9999 from time to time in my CX (D16Y7) I think it's just a software issue.
I was also under the impression that the HX was a 50 state model, while the VX had a 49 and CA variant.

However, Car-part.com shows no selection for CA/49 models. So it is possible one could exist for the HX (D16Y5).

[PaleMelanesian]

I have the same engine (D16Y7). When you see 9999, you're in fuel-cut mode. If you let up on the pedal while still in gear, it's turning off the injectors and not wasting the fuel. That's all that's going on there.

[thebrad]

If that's the case would it be better to stay in gear on our generation Civics rather than go to neutral or EOC?

[PaleMelanesian]

You have to balance it out against the shortened coasting distance. If you're coming in to a stop anyway, go ahead and ride the fuel-cut. Neutral coasting will go farther, obviously, but still use fuel. Mine idles about .3 gph, so at 30 mph, you're at 100 mpg. Not bad. I primarily use EOC, though. I'll use neutral-coasting for a few seconds when traffic demands it, and rarely use fuel-cut. That means I misjudged my pulse rate 1/2 mile back.

[PaleMelanesian]

About the original question, there's someone on Gassavers who did an ecu swap only and says it's working great for him.