E38 Boost and Single Exhaust

[SVTuner]

Hi Everyone,
In the final stages of putting on a single turbo so I've got a couple of questions regarding configuration for boost and O2 Sensors.

In regards to boost, I've done an E40 ECM in the past which required a custom operating system to be applied with HPTuners to suit a boosted application. Is this still required with the E38? I have fitted a 2.5 Bar MAP Sensor as well.

With the oxygen sensors, my vehicle originally came with 2 O2 Sensors pre and post cat for each bank but now I'm running a single exhaust system. Do I still run an O2 sensor before and after the cat and if so, how do you disable/tune for running one bank only?

Sorry if this has been covered but I'm having trouble finding anything relevant with searches.

[5FDP]

Does your computer allow for a 2 BAR OS upgrade?

Click the OS tab to find out. I'd suggest running the upgraded OS if you can, gives you more tables to use and a real Ve table over the VVE (virtual ve).

You don't need the rear o2 sensors but if you have emissions and they check for that stuff or readiness monitors you may want to keep everything plugged in and working. I'm going to use a USA car/truck as the example with the turbo on the passenger side here not knowing if you car is left or right hand drive here. The (left) drivers side front O2 sensor can stay in the stock location in the cross over pipe. Then most people put the (right) passenger side o2 sensor in the downpipe after the turbo and further down than the wideband sensor. Most of the turbo kits sold by people like Trick Turbo or KB Racing have there exhaust setup this way.

You can disable any codes you need too and the cat test and post o2 sensor test in the E38's. That is under the engine diag tab > exhaust.

[SVTuner]

Thanks 5FDP, I'll have a play with the software and see how it goes. According to the following thread, there is a custom OS for E38's for 2.5 Bar so I'll use that. Refreshing to see they are now free

https://forum.hptuners.com/showthrea...ir-Differences

[5FDP]

The custom OS is there on some computers, not all.

[Paz]

Hi Everyone,
With the oxygen sensors, my vehicle originally came with 2 O2 Sensors pre and post cat for each bank but now I'm running a single exhaust system. Do I still run an O2 sensor before and after the cat and if so, how do you disable/tune for running one bank only?

Sorry if this has been covered but I'm having trouble finding anything relevant with searches.

Yeah you most likely won't find anything in searches, i had the same dilemma 2 years ago when i went single turbo.

For the O2s with mine i run the two front ones in my single 4" dump about 700mm from the turbo, i have the two rears still fitted post cats but turned off in the tune.

I run SD OL, tried for a while to run SD CL but it just wasn't going to happen for me at the time.

I also run the upgraded OS.

[SVTuner]

The custom OS is there on some computers, not all.

Checked and yes, it is there