Innovate MTX-L Plus eats Lambda Sensor

Hi, I have installed an Innovate MTX-L Plus Wideband display with Bosch LSU 4.9 sensor on my ATV. Every few months the Bosch sensor is defective and the display gives the error E8. The sensor is mounted 50cm after the cylinder head. I read that the Bosch LSU 4.9 should not start in cold exhaust gases, so I installed a time on controller. Now it starts after 60 sec. Unfortunately, it was not the solution. What should I do? Should I try a heat sink bung extender? Or better another product from another manufacturer? I need a waterproof display.

best regards

Robin

I don't see anything you've done wrong, and trying something new seems a good idea after multiple failures.

Unfortunately, I can't think of a good inexpensive option offhand that's waterproof and has a display face. Hopefully someone will have an idea.

A waterproof CAN based wideband and digital dash would be nice, but probably overkill for what you're trying to do.

Bosch do have a suggestion list for possible early failures - https://store.pic-appalachia.com/wp-content/uploads/2021/08/bosch-o2.pdf

Depending on your specific application, there's a VERY small chance it may be exceeding it's rated temperature(s) - "The maximum continuous operating temperature of the sensor is 930 °C. Sensors should not be used at higher temperatures for a prolonged period. The sensor can be heated to 1030 °C for a maximum of 10 minutes, but this may reduce the accuracy."

As it's a ceramic and metal device, depending on the application, it may be hitting a critical frequency that's causing a mechanical fatigue failure - from what you wrote it's a sudden failure and not over a short period of time?

Hi, thanks for the info! With a new sensor, it takes about 3 months for the problems to begin. In the beginning I have unrealistic values with hot engine, later I always have unrealistic values. The sensor is in the same place as the oem sensor. Yes, the single cylinder has strong vibrations. Oem is a titanium dioxide sensor installed.

https://www.miataturbo.net/ecus-tuning-54/innovate-mtx-e8-error-75300/

When I think about making a heat sink extender CNC, what material should I use? It looks like the oem innovate is made of stainless steel. Would copper be better?

Okay, I'll try again with a heat sink extender. If it doesn't work, I'll change the system. We will make it out of stainless steel. I will report.

I've always wondered how accurately you're really monitoring the exhaust after tucking the sensor up out of the flow path and limiting exhaust reaching it with those extenders with tiny inlet holes in them.

Yes, I also asked myself this question. I'll see if it reads differently

I suspect in steady state conditions you may get similar results, but in transients I would think there's likely a change, data "lost".

Yes, I agree. But on the Dyno, such extenders or adapters are common. I will compare it with previous log's.

Hi, we have now produced the heat sink extender. I removed the o2 sensor and I saw that it was totally red. Why is that so? I changed the oil manufacturer and I drive the fuel from another manufacturer. It wasn't like that before! Can it damage the o2 sensor? I drive normal 98 octane from Esso.

thanks and best regards

Robin

Some fuels and fuel treatments i.e. octane boosters etc. have additives which cause that sort of coloring. It's not necessarily an issue, but could possibly foul the sensor. I couldn't say from the picture.

I do see significant corrosion on the gasket seat of the sensor. If there's significant moisture present, that's not ideal for sensors either.

Hi Mike, thank you for your reply! There is mud on the sensor from the last event, there is no rust, the sensor is only 4-5 months old! Yes, I also read that octane booster produced red color. But I'll tell you something curious. I've been refueling Shell fuel for years and I never had red colour in the exhaust system. A friend has always taken the same fuel on another ATV and he always has a red exhaust system. Now I switch to Esso Fuel and also have a red exhaust system...? When I think about it...I switched to Esso Fuel and I have the new map with o2 off, more fuel and more Spark advance 🤔 maybe the booster is included everywhere and other parameters cause the red color?

thanks best regards

Robin

Ah ok thank you for clarifying that's mud. :)

It's possible if you run the exhaust hot and lean enough the residue doesn't visibly form.

Yes, my son wanted to play something in the mud ☺️

Yes, that's possible, my friend also prog his efi very rich. The red color is also only on the surface, I can remove it with my finger. But why does it is so red? What chemicals are contained and cause this? I read that metal additives are used and they cause the red. I don't know if it's true.

Hi, I wrote to the Shell Company and they answered me the following.

„We assume that this coating is formed by a kind of high-temperature corrosion. These ash-forming components such as ceriums, ferrocenes, manganese compounds or the previously used TEL (lead compound), which are also known as octane boosters, could cause this coating.

According to the law (petrol lead law), these may no longer be used.“

Okay, it sounds like the exhaust gas temperature is the cause. I didn't have it with the oem lean map, I didn't have it with the much too rich map of the other tuner. Now I made the map myself (approx. Afr 13 ) and gave a little more Spark advance and now it's so red. Let's assume it's the exhaust gas temperature, that would also be an explanation why the wideband sensor is game over again. What do you think?

Greats Robin