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GT86 M150

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I bought a GT86 for tuning and for track days (I might inter a local championship). Any way this is a quick introduction.

First modification is an M150 GT86 package (not installed yet).I have a lot of question about this, but first thing first "Installation".

Can I tune with the stock O2 sensor? How accurate the stock sensor is? I can see 2 sensors on the stock headers one must be the wide band O2 sensor, and the second one must be the narrow band sensor. Which one will the motec display? Or will I be able to display both?

I also got the Bosch LSU 4.9, 5 wire sensor with MoTeC’s LTC modules. I want to extend this wire. My question is from where do I extend? Do I extend the wire between the Bosch sensor and the LTC? Or from the LTC to the ECU?

I'm holding on installing the Bosch sensor till I get an after market headers. But it's on back order and I want to start tuning.

I also want to install an oil pressure sensor. Where do you think is the best place to install ? And what type did you go with?

Thank you

You need to use the Motec LTC with the Bosch sensor. The 86 package does not support the factory O2 sensors.

Extend the 4 wires (12V+, negative, Can + and Can -) between the ECU and the LTC.

Install the oil pressure sensor in the same area as the factory oil pressure switch.

Will do. thank you MSEL.

Is there any reason not to do it the other way?

I know the Bosch connector has a jumper. Is it that two jumpers won't work? Can't I disable one of them?

Or is it because there might be a voltage drop between the sensor and the LTC, and the LTC must be as close as possible to the sensor?

The reason I'm asking is to educate my self, and for any member to benefit from this post.


The LSU 4.9 sensor has a calibration resistor in the connector hence you can't replace this connector with a DTM or similar connector. I can't see any problem however extending the harness between the LTC and the lambda sensor. This is how the Motec PLM is wired on our dyno and we have about 3 metres of harness between the PLM and the NTK lambda sensor.

The main reason we do not extend the sensors is that when it comes time to replace the sensor, you have to modify the new sensor before it works.

Sensors never fail at the best of times so it is always easier to be able to replace it with something off the shelf.

If you want to exend the lambda lead, use a proper extension loom. Both mating halves are available seperately.

Whatever you do, DO NOT EVER SOLDER lambda sensor wires. They MUST be crimped.

extend the wiring from the LTC to the Bosch Connector, do not extend the wiring on the sensor itself or replace the connector on the sensor side, as there is a calibrating resistor between PIN2 and PIN6.

this might also be a good read: http://wbo2.com/cable/lsuconns.htm

Yes. That's the website i ordered the connectors and they're DIY wiring.

(1) LSU-4.9 plug (2x3 mates with CNK17025) kit == PLG17025x1

(1) 6 pin (2x3) LSU-4.9 cnctr kit == CNK17025x1

(1) 2.6 m DIY cable == DIY26CBLx1

At first i didn't know that i can get the male plug with out the resistor. But after searching i found the website you posted.

But really thank you all for the help. All your reply's (MSEL ,Andre, KGPerformance) confirms that I'm on the right path.

We usually reply within 12hrs (often sooner)

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