Oxygen Sensors Failure

[Wayne&Judy]

Does anybody know if Mercury is still having problems with oxygen sensor failures? I own a 2011 240 SunDancer, this is our third year of owning this boat. While out for Mother's Day we had a oxygen sensor failure. Mercury waited over a week before their rep came and looked at it. Our marina has a authorized repair facility for Mercury, but because this part is still under warranty we had to wait for the rep to tell mercury what the mechanic had already called and told them They sent the new sensor it was put in then we went for a test run, it failed immediately, mechanic called back Mercury, they said to swap it out with another sensor, did that, out again, another failure, mechanic said the new sensor failed. So Mercury is sending another new sensor. Sounds to me that something else might be the problem. Our warranty is up this September and I'm afraid Mercury is giving me the runaround. Any suggestions or has anybody else have similar experience. Worst thing is this is Memorial Weekend with beautiful 80 degree weather and my three year old boat is down. Bought a new boat so I wouldn't have problems, this is the third year we've owned this boat and every year we have had a problem.

 

[spfortjohn]

Join the club. Ran into my neighbor today at the sandbar. His 2011 250 SLX with the 350 MPI has the same problem. He was in his 14' yamaha powered center console. He is sick of the problems

 

[Chris Nowell]

The warranty people at manufacturers' head offices have no empathy for the customer whatsoever. Every step of the troubleshooting process has to be verified by them in our shop, and I'm sure it's the same with "Merc Marine". Even though everything is computerized our guys are still required to print "wellness" reports from the ECM and submit them to corporate before any work can continue, even when we know what is causing the problems because we've been dealing with the issues hundreds of times over the course of many months. Then we have to wait for permission to go to the next step, and the next one, etc etc. If any of our warranted parts aren't in an OEM box and all the I's aren't dotted and the T's aren't crossed on the paperwork the manufacturer refuses to reimburse for the part. In a nut shell, they are making it extremely hard to provide the level of customer service that we strive to provide, and I'm sure the same applies to the Merc dealers an the "front lines". Our jobs and income rely solely on providing unrivalled service to our customers. The people who process the warranty claims at the manufacturers' corporate offices have jobs that are secured by "getting the numbers up". Hopefully they'll resource the part eventually and do a recall or a service bulletin of some sort. Hang in there and good luck.

 

[B&AKearney]

We have the same problem. Out with our brand new boat (it is a 2011, it was a leftover we purchased over the winter) for the first run of its life and the alarm went off regarding this fail. According to other forums, Mercury doesn't know how to fix it just yet...we'll learn to live with that annoying buzzer.

 

[PlayDate]

You won't take much comfort in this but this is an engineering issue that at it's root is emissions related. In gas race boats, the only way an O2 sensor can work is in dry exhaust. The ones I have worked on use wideband O2 sensors to dial the motor in on the dyno (with typically a FAST aftermarket ECM) and then use the saved Air Flow and Fuel flow ECM tables on the water.

The reason why is that a small amount of water will basically destroy an O2 sensor. Mercruiser is trying to solve this using higher risers but the problem remains. I seriously question this approach and its perceived benefits. The theory is that by monitoring the exhaust gases the fuel required can be better controlled with less emissions. While this is largely true in cars, marine environments are not equivalent environments. If you think about it, boats have three speeds: idle, cruise and wide open. Cars operate over a much larger range where fuel adjustments can have greater impact on emissions. I would bet money that a "experienced" set of static tables will match operating with an O2 sensor and may actually outperform it in a marine environment.

Left to their own, I'm sure Mercruiser would prefer to stay with non-O2 sensor EFI systems but it is not up to them. The government wonks want O2 sensors and catalytic convertors installed on all boat engines and have been pushing this agenda for some time. Mercruiser is stuck in the middle as they are with E10 and E15 and all the other nonsense that the EPA orders them to do.

-John

 

[Wayne&Judy]

Update on problem. Now Mercury thinks our problem might have something to do with the fuel filters. They are sending new ones to replace plus one more oxygen sensor. Hopefully this will correct the problem but from what I've read the engineers at Mercury still can't figure out how to correct this problem. Will keep everyone posted. I have been wondering I know the 2011 models have a problem, but has anyone heard if 2012-2014 models are having this problem or has Mercury figured out what went wrong.