Just replaced both my primary O2 sensors because of a rough idle/limp mode when idling. My average MPG went from 20 to 32. Easily worth it!

Love these random experiments, I think you should buy some new O2 sensors and make another video 🙂

Hi Ban, may I ask where did you buy that lifter Jack? Thx

I read in the bimmer forums using a sonic cleaner (like a jewelry cleaner) does a much faster and more effective job removing the deposits. I have an X5 Diesel that keeps flagging the lower O2 and will be giving it a go

What kind of aftermarket 02 sensors are you using?

I have a 2011 X3/F25 30d with 251,000 km, and I think I get the best fuel economy if the average speed is about 70 km/h. I use to measure between refills. But if the measurements are at slightly different speeds the consumption will vary, and then it's impossible to judge the "work" done or the result of it, unfortunately.

With "renewed" A/F O2 sensors the engine will burn and breath much better for sure. In addition driving speed highway always will help to tun the engine, to clean it and therefore it works better and it means more MPG. BimmerN53

Thanks for "general public debunking myths" vid. The O2 sensor doesn't care about carbon buildup ... it it will get clogged up it will start reporting super rich, which will cause leanout of mixture that will raise the temp and provide more oxygen to burn up anything that clogs it up. Only problems with lambdas is a genuine failure, that can't be fixed by simple cleaning. Failures are a sign of sensing element chemicals failing due to corrosion (bad fuel) / aging / being over heated (heavy tune that goes very lean for odd reason) - leading to giving wrong readout. Also, even catastrophically failed lambda is not that much of a problem because any ECU in last 20 - 30 odd years will figure out that reported values make no sense based on rpm + throttle possition + boost pressure / amount of fuel put in, and simple switch to open loop control ignoring lambda and worst case will go into limp home mode.

I think you will need new sensors. They pre-cat ones last for a max of 80k miles, without a tune. Have a great week. Dutch regards, Nico.

That sounds about right for the mpg. Can't remember if you have a tune on it or not. I had mhd and got around that on my 335 if I wasn't doing highway but mine was x drive so that may be a little on the low side. I know my sensors weren't all carboned up like that tho. Down pipes are so much easier on rwd. I had to drop my sub frame and pull the engine mount to do mine on the awd.

The best way to get better mpg, to check smoke test on intake, I didn't buy smoking mashine yet, I am sure that I have air leak..

Tbh when I replaced my o2s I gained like 4mpg I thought it was worth it

Thanks!

How the hell are you getting 21.1 mpg ? My 335i gets 15 to 17 mpg. Some highway but mostly city so I'm not shedding too many tears with your mpg.

Thanks u stoped me to clean my o2 sensor

1) didn't want to see the car wash, but 2) at least the code went out. I'll have my brother do this - to see if my code goes out. Thank you

I wouldn't be able to record myself doing emissions tampering by putting in downpipes. 🤣 test drive in the track.

The RPM on my Z4 won't stop spontaneously dropping and killing off my engine now 💀

17mpg on 335is with city and some highway driving.

Yeah I need to try this on my m4 I swear to find I’m losing so much gas it’s not even funny anymore

ultra sonic bath

Lol my 328i n52 gets 15 mpg……..

Wow bmw’s have complicated builds. On Toyotas you just reach down and grab it haha

How much are the pair of o2 Sensors?

Why would it change if you didn't CHANGE THE TUNE 😂

Why would you clean at that mileage ? OEM aren’t even that much $$

Bro I can’t get passed 18mpg 😭