Skip the auto shop - Our mechanics make house calls

Q: Sulphur blocking the catalytic converter

asked by on

My car has the dreaded injector coil issue and I’ve already replaced it two times! Currently, it is running better but the engine management light comes on randomly. The dealership told me this is caused by sulphur blocking the catalytic converter. They blamed me that this is caused by the way I’m driving. I was also told by a tech that my car is remembering how it used to be driven (ex-fleet car with mostly highway miles). Now that I own the car and it’s not being driven as much as before (I just drive around town and shopping) this is the cause for the sulphur blocking the catalytic converter. He said it’s not a warranty issue, but instead the way it’s being driven. His solution is to desulphurise the car and this can be done by my regularly driving it on the interstate at 70 mph for 30 minutes. This seems rather impractical to me, plus such a bother! This was also questionable because I was driving on the interstate the second time the warning light had come on and was going over 70 mph. When I bought the car I was aware there was an unlimited mileage warranty, so I don’t think it’s unreasonable for me to expect BMW to honor this! If a car can’t perform well on short trips, then there must be something wrong with it! This is a petrol engine - not some diesel engine. In addition, I was told that the blocked catalytic problem can be caused by the injector coil. To add to my problems, when I got my car back from the garage, there were fresh scratches on the front, side bumper!! I will call BMW about this also. Would you please give me your advice, diagnosis, and solutions for my car?

Hello. If you had an injector coil issue, then that will usually cause the converter to become clogged and fail. If it is clogged, then it needs to be replaced as driving it will not clear it up. You will have multiple failure of the coils over time until they are all replaced. Since you have the unlimited warranty, then this should be covered. I would advise that you call BMW’s national customer service line to get them involved as they should be able to offer more assistance. If you would rather have an independent technician inspect this, a certified technician from YourMechanic can diagnose the warning light that you are experiencing and let you know what next steps are needed.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Car dies after a few minutes

There is a high possibility that your fuel injection unit "CFI" is malfunctioning. That is a common problem on your vehicle. If you would like help with this issue, consider YourMechanic, as a certified technician will be able to visit...

Q: lights came on car clunking pulled over

Hello, thank you for writing in. A clunking noise can unfortunately stem from a wide variety of issues. The first step is to determine if the clunking was engine related, exhaust related, or wheel related. All of the above will...

Q: When the car reaches 54km, 76km, or 101km. to 108 km - there is a steady drone noise. Above or below numbers given it goes away

Hello. This may be related to many different things. One of the most common droning noise sounds, however, is the sound of worn wheel bearings that need to be replaced. This sound will be produced at higher speeds as you...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...