I have been using W/B 02 sensors on my fuel inj Camaro for many years, but didn't think it was possible on a marine eng since water is mixed with exhaust. I just stumbled across this site and I see you guys are doing it. How do you sample the exh without getting water on the sensor??

Has anyone adapted an automotive ECM for marine use?

You have to run dry pipes ... dumping the water @ the tip .
I have run air / fuel sensors for years without any problems . AEM is the brand I use and had to make a 20 ' harness from the sensor to the gauge. Mount the sensor @ 10 , 12 or 2 o'clock on the pipe . You have to fabricate a tail pipe with an o2 bung welded in .

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I ran an O2 sensor in the exhaust right before the water mixed in the header. I only ran it when I was doing occasional test or after re-tuning. Don't remember the brand but it was an entire kit (I've since sold the boat)

Were either of you monitoring the exh on an I/O? Seems like the eng compartment would get really hot, really quick, especially at WOT.

I have the AEM sensors in my CMI's They are right where the tails connect to headers where it is dry. 3 yrs, no issues so far.

Smitty

It's easy. Either have an O2 bung welded into the dry section of the exhaust or, the easy way for those with stock or stock type marine exhaust manifolds is to use one of several wide band O2 spacers that fit between the manifold and riser.

The spacer has a spot for the sensor to thread into keeping it in the dry section prior to where the water dumps in. The spacer has holes for coolant to pass through from the manifold and into the riser.

I've been using an Innovate wide-band O2 for several years. It works great. It was instrumental and necessary for EFI tuning.

Here's one example. No I'm not affiliated. In fact I didn't use this brand. Mine was a WAGs engineering piece.

http://www.ebay.com/itm/OXYGEN-SENSO...s_Gear&vxp=mtr

The exhaust system is completely encased by water cooling passages. I can keep my hand on the exhaust manifold when it's running. If I can't then I have a cooling problem.

Short answer is the engine compartment gets warm but not hot.

When I ordered my new IMCO Powerflow manifolds, I had them weld the bungs into the risers. I used an Innovate wide-band O2 sensor to check and test A/F, and yes I did connect the I/O to my laptop to capture the data. Most manufacturers will weld the bungs in, if requested for an additional charge.

On My Donzi I made a spacer between the riser and the manifold.
On my Magnum they are installed on the tailpipes before the water is injected.

Both boats run a GM 7730 Speed Density ECM.

Jeff