Has anyone successfully installed O2 sensors on the 496HO stock exhaust manofolds?

Thanks!

Rage,
Why????

To dial in proper air/fuel ratio when changing to high flow heads, intake manifold and cam so as to prevent detonation.

O2 sensors arent very common at all in marine applications, they are commonly used on the dyno to tune the motor but thast done with dry exhuast.

So...you can RE-Tune your ECU with a laptop while you are driving the boat with sofware from who?

There is no real way to install an O2 sensor on stock 496 manifolds. The problem you will run into is trying to keep it from getting wet. As soon as that wide band gets wet she is usually done working. However, I do it all day long on CMI exhaust. I would think if you are installing new heads you might want to consider getting rid of the old manifolds anyway. That is very smart of you to be worrying about the O2 sensor when replacing heads. What efi system are you using? Thanks Cam-shaft.

axapowell,


Actually there is no plans to touch the ECU which I prefer to retain as stock. If the A/F ratio is too lean I would increase the fuel pressure and rerun until it comes iton the desired range.

Cam-shaft,

Thanks for the response. From what I have been reading the wet exhaust did appear to be the main problem for using an O2 sensor with the stock exhaust manifolds.

The ECU is the stock Merc for the 496HO. I am taking the DIY low tech/low cost approach and want to retain the stock exhaust manifolds and all the fail safes built into the Merc ECU unit as well. No dyno time in my future.

Any other way to confirm appropriate A/F ratio other than trying to 'read' the plugs?

I have yet to see a fuel/air ratio meter that works well, and then to add the whole water thing. Was just wondering if you had a way to reprogram the ECU and who designed the software,

Good luck with the o2 sensors. Like to hear how you make out.

Dave

Doesn't the stock computer on the 496 have it's own sensor in the exhaust manifolds to make it's own adjustments with air/fuel mixture?