Hi folks,

My wife has an 07 MC and for almost a year it ran flawlessly. Starting in may however, she got the dreaded cat converter CEL and took the car in. She got the standard talk about dirty gas (she fills up at Phillips 66, so I didn't see any problem with that) and using premium with no ethanol. Well, I personally think that's bull, but my wife agreed to follow their advice and start using premium at the "top tier" places. They also gave her a bottle of their fuel system cleaner.

Anyhoo, a month and at least 2 tankfuls of gas later (on top tier premium), the engine threw the code again. Took it back in, explained that she faithfully followed their recommendations, so they checked it out again promising to fix whatever is needed. Well, when she got it back, they basically did the same thing as last time, that is cleared the code and ran some tests. Nothing else. So, I am pretty much expecting this to happen again soon, and we have a long trip coming up in about a month. I honestly don't have enough confidence in the car for such a trip until this issue is fixed, not band aided.

Anyone get to resolve this issue permanently? What did your mechanic do?

Thanks in advance.

Daniel

 

Low cat efficiency means your emissions will be higher. The catalytic converter is an exhaust component, doesn't affect anything else, and should not cause any lack of confidence in the car being able to do a long trip.

Catalytic converters are covered up to 8/80K by federal law, so start harassing the service manager.
http://epa.gov/otaq/consumer/warr95fs.txt

 

Thanks for the info Splicer. The tech did a suite of tests each time and all the tests passed... presumably this included the catalytic converter, although the sheet didn't say it specifically. His conclusion was that it was a batch of dirty gas in each instance, causing the o2 sensors to read a cat converter problem. So, in essence they're blaming the whole thing on the gas, they say nothing's wrong with the car.

I'll pursue the cat converter suggestion though, maybe I can get them to bench test it to see if it's up to spec. Btw, the reason why I said I can't rely on the car is that whenever this happens, the car runs like cr@p when cold and mileage really sucks. Plus, my wife refuses to drive it when that happens, so if we do get this condition during the trip, our vacation is pretty much screwed... and since we haven't had a decent vacation in over three years, this is pretty important to both of us. I have been seriously considering driving mine, even though the mileage is not as good and it's coming up on the end of its warranty.

 

My car is also an 07 Cooper (May build) and my CEL light came on about a month ago. I brought it to the dealer and the fault code was 276A cat converter efficiency. They said they needed to change the Cat converter, which was done last Friday. Hopefully it is now fixed. Next time you get a CEL perhaps you could have someone with an OBII scan it for the code. I hear some auto repair stores will scan it for free also.

 

Ahh, yes, same code as my wife's car. So, they did change the cat converter then? Maybe I can talk our SA to do the same. Please keep me/us updated on how well this holds up for the next year or so. Similar to yours, her car is just about a year old now.

As far as obd codes, there is a writeup in one of the 2nd gen sections here that shows how to read (and even reset) OBD codes without a reader. The next time this happens, and I have the chance to do it (she took hers straight to the dealer as soon as the CEL came on), I'll read the codes myself and write them down for future reference.

Thanks for the input, now I think I have a strong enough case for a new cat converter if this ever happens again.

 

If you have other driveability issues, the chance of those being caused by a 2 year old catalytic converter is very small. Your tech is probably right that it is just a symptom of some other problem. The 'bad gas' excuse is probably BMW-mandated stalling to make sure there really is a recurring issue before doing expensive warranty repairs. I would not press to get the cat replaced but I would get on them to start taking the issue seriously and emphasize the other problems you are having.

BTW what do you mean by "running like crap" and what kind of mileage does it get when it's acting up?

 

That's true, unless the converter was defective. The car is a july 07 build, so it was about 10 months old when the first CEL happened.

As to driveability, I drove it shortly after the first CEL came on. When cold, the car would idle rough for the first half minute or so, then the idle would smooth out. However, even after warmup, the car felt like it lacked power, and the OBC mileage was significantly lower than before (by 5-6mpg, somewhere in the high 20's). I drove it shortly after they reset it the first time, and the rough idle was still there in the morning, but the power was back and the mileage was back to normal (low to mid 30's). I have to say that the first time they also gave us a bottle of fuel system cleaner to put in. We filled up the same day we got the car back (with 66 premium) and added the bottle, but the rough idle never went away.

I haven't had the chance to drive it since the second reset (they didn't give us any more cleaner), but according to my wife the cold idle was improved for the first few days. However, my wife just called me not too long ago to tell me the rough idle is back. The CEL isn't on though, so not sure what's going on there.

Another thought crossed my mind, what about something like an intake air leak? Someone with an MCS mentioned a crack in the plastic intake. I figure anything that would cause the car to run extremely lean (or rich) would affect converter efficiency. That would kinda explain the cold rough idle, a leak that would partially seal when warmed up. I dunno, just guessing at this point.

Thanks for the help and advice.

 

The only way a converter is going to cause a problem with idle is if it was clogged up. That doesn't happen in 2 years unless there is something seriously wrong with how your engine is running (something that would have lit up the CEL long before now).

The intake air leak is a good theory.

 

Yup, I agree. I'll keep updating this thread as I find out more. Cross fingers.

Daniel