Do I need to change catalytic converter along with Risers/Manifolds?

[rpasquarello]

So, I am coming on the time in which I think I need to consider replacing my risers and manifolds. My problem is that no marina is thrilled on working on my engine!

I have a 2010 mercruiser (splashed in 2011) 260hp ect mpi that is raw water cooled (it does have a Volvo Neutra Salt system I added in 2012) and has those lovely (note the sarcasm) catalytic converters installed -- which merc started adding in 2010 to meet some new regulations.

My usual winter marina told me flat out they they won't go near it and another that I may switch to (as a result) is cringing but, so far, will do it -- but I am awaiting on their estimate.

So my questions are these:

1. If I am not running hot, at which point in time am I pushing the envelope by holding off on these replacements?

2. Can I just do the risers and manifolds and leave the existing/old cats?

3. If not, how much more will this add to the time/cost (materials/labor) that I will certainly get slammed with?

4. Anyone do this yet on Long Island?

FYI, I have not yet called Merc as yet to ask.

Thanks,

-Rocco-

 

[skibum]

Here you go...

http://www.cpperformance.com/p-16709-max-volt-catalyst-eliminator-computer.aspx

 

[rpasquarello]

Here you go...

http://www.cpperformance.com/p-16709-max-volt-catalyst-eliminator-computer.aspx

Thanks for the reading material!

 

[Bt Doctur]

If it was me, I`d install standard manifolds and risers, maybe even go for the "dry-joint" ones.
Screw the EPA

 

[skibum]

If it was me, I`d install standard manifolds and risers, maybe even go for the "dry-joint" ones.
Screw the EPA

How would the ECM respond to that? Seems to me that he'd need to put an '09 ECU on it so that it wouldn't be looking for input from the O2 sensor(s). I've bypassed the post cat O2 sensors on several car engines, usually with a resistor (or resistors in parallel when an odd value was required), but the pre-cat O2 sensors are usually responsible (or partially responsible) for the air/fuel mixture so I've left them in. I helped a friend install headers on an early 2000 model GM truck engine, and we had to drill and tap a hole for the pre-cat sensor to make the ECU happy. Another friend used a spark plug anti-foul adapter to pull the post cat O2 sensor out of the exhaust flow so it would stop throwing codes. I have no idea how Merc implemented the sensors into the equation. It's all BS anyway. Catalytic converters spew platinum, palladium, and rhodium dust out the exhaust as they age. In my opinion, that is far worse than CO, CO2, and everything else a fairly well tuned engine without cats puts out.

Just another example of government regulations run amok. All life on Earth is comprised of carbon and water, yet our government has fooled the population into believing that they are "pollution". Carbon emitted into the air has mass, it will eventually fall out of the air (or get brought down by rain), settle into the soil, become a plant, which will be eaten by an animal, which will be eventually be eaten by humans. It produces or sustains life at every stage. Therefore, we must ban, or regulate it. Makes no damn sense. It's all about extracting money from people. Sickening.

 

[BillK2632]

I would give Merc a call and see what they have to say. You can't be the first person to replace an exhaust manifold or riser on a catalyst engine. As far as getting rid of the catalytic converter - I would make sure I knew what I was doing, pretty sure the ECM is not going to just party on without the O2 input.

 

[Fred]

I'm just guessing here, but systems with catalytic converters are usually designed to last a long time. I would expect many parts of your exhaust system to be stainless steel or some other none corrosion material.
I would check this out before replacing any parts.

 

[rpasquarello]

Update: I spoke with Merc today. They indicated that it should not be such a big deal. Cats do not have to be replaced -- just the risers and manifolds and maybe some canister that goes inside the cats. Everything else should be able to be reused like the O2 sensors.