Sale ends todayGet 30% off any course (excluding packages)

Ends in --- --- ---

Portable wide band o2 sensor - "Easy positioning"

General Tuning Discussion

Forum Posts



Tech Articles

Discuss all things tuning in this section. News, products, problems and results. 

= Resolved threads


Hi All,

I'm looking to buy the portable Innovate LM-2 wide band sensor to assist me with accurate data. But how do you "easy" mount it to the car (the sensor element), since it needs to be fitted upstream? Do you take the excisting o2 sensor out and replace it with the Innovate? but then the car can't run in closed loop.. It's no use fitting it to the back of the exhaust, since this is downstream.

Seem like at lot of hazzle to go through, or am I completely missing something here? :)

Best regards

Simon :)


While yes, mounting it 500 mm from the exhaust port is best, this is a practical alternative if fitting the sensor is very difficult.

Expect slightly leaner readings at low rpm, apart from that, depending on your application, this tool can work for what you need.

Be very careful to make sure that the sensor always points upwards, between 10 to 2 on a clock, especially when removing the tool. The condensated water inside will kill the sensor instantly.

I use the Innovate exhaust clamps on my dyno sensors. I have found that I usually need to safety wire it so that it can't fall out. I just run run the wire forward to a clamp or exhaust hanger, and wrap it around some part of the clamp so it won't fall off.

As Dom mentioned, I can't typically fit the clamp so the sensor is pointing up, so I just don't install it until the car/exhaust has been warmed up.

Hi U2

Thanks for your reply! But how can you use it for tuning, when you fit it after the catalyst(downstream)? Then the exhaust gasses does not represent the combustion AFR anymore.

I would like the reading before the catalyst, otherwise how can I use the data?

Look forward to your reply☺️


Do not worry about the inegrity of AF data post Cat. I do understand that this seems to be hard to get the "head around", but it is true.

Take into consideration the time delay of the signal when the sensor is placed at the end of the exhaust system. In my experience though, this is more of a concern when you record AF data with the goal to pass emission drive cycle (vehicle homologation procedure). For plain performance tuning, this time delay can almost be neclegted.

Thanks a lot for you anwser, and so sorry to asking again :)

But are you sure that the AFR we measure post cat is the same (or similar) as the AFR we measure pre cat? I mean, after the catalsyst the exhaust gas composistion has changed due to the chemical process in the cat, how can it then represent the combustion mixture?

I mean, doesnt the cat store some of the oxygen?

No. The same gas element (the carbon, hydrogen, oxygen, nitrogen, etc) balance of the compounds entering the catalyst is the same as that coming out, it just may be arranged into different compounds (CO, CO2, H2O, NOx, etc) as the catalytic converter 'shuffles' them to give more acceptable emissions.

For a simple single gas analyser, like the lambda, it shouldn't be an issue, but if you can afford a 4/5 gas analyser it can make a difference as that tool is good for checking combustion efficiency by checking gases the cat' will break down.


Thanks a lot for clearifying this for me! That was exactly my concern, but know I also know how to fix the sensor to the back of my exhaust:)

I really appriciate all your anwsers, thanks so much.


The wideband Lambda and the narrowband O2 sensors compare the ratio of oxygen within the exhaust gas stream to the ambient oxygen.

Since the Cat does not reduce O2, the readings remain unchanged.

The Cat reduces CO, HC and NOx.


Hi Dominique,

Thanks a lot for your feed back!


Hi Dominique,

Thanks a lot for your feed back!


My pleasure Simon. Glad you found the information you were looking for.

Best regards


We usually reply within 12hrs (often sooner)

Need Help?

Need help choosing a course?

Experiencing website difficulties?

Or need to contact us for any other reason?