Re: O2 Sensors on 496HO??
 

No those are temp sensors in the manifolds, not 02.

Re: O2 Sensors on 496HO??
 

What are there purpose then? Do they sense a higher temp when running lean and add more fuel? Or do do they do something completely different?

Re: O2 Sensors on 496HO??
 

I dont beleive they have anything to with running parmeters they onl effect the guardian system, becuase it is closed cooling you would't know if you lost a se pump for a couple minutes and this way you know pretty quick.

Re: O2 Sensors on 496HO??
 

ok, just wondering.

Re: O2 Sensors on 496HO??
 

axapowell,

Thanks, but it looks like the O2 sensors on my set up is a non starter. Probablty just as well given the reliability issue you describe.

Re: O2 Sensors on 496HO??
 

You may also be able to change to larger fuel injectors at the same fuel pressure to accomodate the increase in airflow. The computer wouldn't know what size the injector actually only sending pulsewidth instructions based upon the program of the computer.

Re: O2 Sensors on 496HO??
 

Looks like round two on the O2 idea.

I think the O2 stops at the end of the boat ramp....It's in my truck :D :D :D

Re: O2 Sensors on 496HO??
 

It's easy, remove a riser, drill a hole approx. 1" above flange on the outer side of riser. Use a stainless bung, which you can get from Imco, CMI, etc. with a step in it. Weld the outside, then weld the inside. You will need to repowdercoat or paint the riser. I've done it quite a few times, very easy to do. Always replace gaskets when removing so you ensure no leaks.

Thanks,
Dustin

Re: O2 Sensors on 496HO??
 

Dustin,

Thanks for the guidance!

So on the stock Mercruiser risers you install a SS bung for the O2 sensor that will pass through the water jacket and is welded on the inside tube and the outside tube located one inch above the flange? Very good!

Any suggestions on what O2 sensor monitouring equipment to purchase/use for this kind of onboard testing that will work but not break the bank?

Re: O2 Sensors on 496HO??
 

Dustin,

Which gauge do you use? The ones I've seen just look like a disco light moving up and down.

How do you weld inside the riser(pipe) to assure a good seal. Seems like tight quarters to get it right.

Dave