I have to back up here as I could not remember what in the hell fault code 219 was. Basically I kind of thought since the your mechanics blew it off it was just something not to worry about as they cleared and or fixed it. Not sure here any of their thoughts or actions. just saying

Anyways thought about it so here it goes. Your overspeed most likely is from this fault code 219. this code is the electronic shift control = ESC - so the PCM is sending out commands for the ESC to move positions but the position sensor is not confirming any of it so the PCM can not find the position of the ESC. Hence the fault code 219.

the ESC is also called the shift actuator in which is a small electric motor to move a shaft that puts the engine / outdrive or if a transmission app in Forward or reverse or Neutral as inputs from the electronic remote control via the command module and the PCM. Also the ERC = electronic remote control send the throttle inputs electronically as well to the engine via the command module and PCM. FYI. and this is all part of DTS = Digital throttle shift and PCM 09 calibrations.

You need to find a current certified Merc & mercruiser dealer and request the Merc area rep to help aid with the diagnostics and repairing of your app correctly and properly. the Merc area should be able to assist with the current OEM dealer. Just saying

hell I was just up to Buffalo for the run.

Thanks for the info again much more knowledge than any other mechanic around. I'm debating going to tech class and learn the engine inside out as no one seems to have the latest knowledge base locally. I found a manual on line that had the 219 and it is as you described. Will have to research some more on tweaking it. If I recall it will reduce the power by 5% until configured properly. With beer in hand and staring at the CAT yesterday I decided to remove the pre CAT O2 and replace with the post CAT O2 that was leftover after I put the new O2 in post CAT. Pre CAT O2 was in worse shape than the post CAT O2. Started the boat and still got the alarm. Went out for a cruise and on way back in noticed the alarm had cleared. Went out again and no alarm. 1 down, 1 to go. Appreciate your feedback.

Can not believe the service manual is online. Merc has been trying to get rid of all this little by little online service info as it really is copy right infringement as well. Anyways kind of not fair for the dealers who have to spend thousands for special tools and manuals and so on when a person or a do it your selfer who basically spends nothing has it at there finger tips for free. Just saying as we all like free stuff including myself.

Currently and coming within a year max - the 02 sensors pre and post are not the same. Post (rear) CAT 02 sensors are now real wideband 02 sensors. Your app being an older CAT app all 4 - 02 sensors are the exact same . just some added info

It is very important that the CAT and its space within maintains the correct amount heat on both ends - not too cold nor not too hot. For the CAT to work correctly it needs heat of 600 min to 800 degrees. With that said engine cooling is now more important than ever.

Make sure your check balls or check valves - one for each manifold and one for each riser (located in bottom of each) are not restricted nor stuck or broken apart. Also make sure the poppet valve is the same and working correctly.

Thanks again. Will check it out.

I have exactly the same prob: stbd system fault 217! What can I do?Thank you

" What can I do " ^^^^^ bring me your boat so I can fix it properly and make some money . Heck its winter and I'm almost caught up with boats.

Have no idea what app and year model and engine serial number here. plus the set up and is this a stock app ? Im not throwing darts and do not want to go thru guess work without any of that info. Sorry man hopefully understandable.

Merc 5.7
 

We bought a 2012 Sea Ray Sundeck 240 with a Mercruiser 5.7 Bravo. Since we bought it we are getting a code 48 stbd exhaust oxygen sensor not working properly. We had our mechanic replace the precat sensor and reset the code. 2 hours later we got the same code so he replaced the post cat sensor. Not even an hour into that we got another code 48 and now are getting a code 50 as well. Any thoughts? We are extremely frustrated. Thank you.

^^^^^^^^^^^ In this thread I Posted alot info here to help out catalyst engine boat owners. My experience one I am trained indepth on Marine catalyst systems, 2 is Cat engines are not for everyone to work on especially with no experience. I see more boat owners and incompetent service shops cause more harm than good and in return really causes huge expense to get systems fixed correctly after the fact.

Two - I hate when I spend my time to offer very solid indepth FREE info that I had to pay for to gain and that person never comes back up to say it fixed it or not. They disappear once they get what they want for info like the poster above. The dude made 5 total posts here on OSO but failed to comeback up for the 6 post to give updates. Anyways --- you need to post your engine serial number - hours on the engines and was the shop that work on your app competent ? Also is your app totally stock ? and is your exhaust totally stock ? do you have captain call exhaust ? meaning switchable exhaust -

I would be more than happy to take the boat to you for repair but I am located in Pennsylvania and I believe you are in the southwest from what I have read. I will have to go down to look at the serial number as I dont have it here with me. In answer to your other questions, It is a stock motor, 160 hours, our mechanic is a Mercruiser mechanic who seems to be competent? but unfortunately, we do not have a lot of boat mechanics around here to choose from. It is not a switchable exhaust. It is a 5.7, 350 Bravo, Mercruiser engine. Ill try to get you the serial number today but we are suppose to get storms so I dont know if that will happen. I'd be happy to report back to you with what happened. I have no problem with that at all. I appreciate any help you can give. Thank you

I understand that you are not close as if you were mostly likely you would called or some how the path would have crossed for your issues maybe in my hands. Just like its does for the 496 marine apps. Seems like that crowd always finds me or I find them. Just had a guy from Kansas bring me his boat with a 496. He basically was stuck with not getting his boat fixed correctly and got tired of parts changing and spending money. Anyways.

You will have to give me your engine serial numbers. There could be updates and service bulletins and so forth that never got done and or needs to be done as engine serial numbers determine all that plus your stock OEM set up. Did you buy this boat new or used - what kind of water did it boat in past and present ? meaning saltwater or - brackish or clean fresh water ways

what are your operating water temps at ? at idle and mid range and WOT ? .