NOOB questions - What do I need?

[Carguy123]

I am wanting to put the LFX into a Miata. I've read several build threads and all of them end up using HPTuner to get rid of VATS and turn off the rear O2 sensor.

In the Honda world as long as I keep the key and ignition switch/sensor I don't need to get rid of their Anti-Theft system. Does GM do it differently?

If my car will have to be street legal can I turn off the rear O2 sensor?

Why am I turning off the rear O2 sensor?

Is there something else that needs to be "tuned", other than to get more power, or could I still install a completely stock ecu & engine and make it work?

I have not bought HPTuner yet because I'm still trying to see #1 do I need it to make the system work initially and #2 what are the benefits or necessity of tuning the ecu other than more power?

If I don't have to buy the software to get the system the temptation is not to buy it until I at least have the car running and driving. In other words I'm trying to keep it simple initially to increase the odds of me actually completing this swap.

If I find this is as good a swap as I think it is I will have a 2nd autocross only car that I'd like to also swap the LFX in but make it an automatic and for that I know I'll need the software.

Can you swap the LGX? or has the software changed enough that HPTuner can't deal with the newer ecu?

[cyrus_the_great]

if you can swap LFx so you can do LGX ... lately swapped LFx into my 1990 cutlass ciera and can ay hptuner not fully compatible to e39 ECMs.

[Carguy123]

And yet William Henn @ HPT said that's the one to get. How'd you like the LFX in the Ciera?

But that's the reason I posted here because after a long string of emails I simply couldn't get a straight answer from them and yet some posts seem to show issues with the e39 and e39a

The LGX is bound to be more expensive, but reading Wiki it appears that it has better cooling in the head so would be better for track use.

So can I use the ecu without the HPT to at least get it running and sorting out all the wiring, etc.? I'm sure that once I've got it running I'm going to want to get more out of the car, but I like to keep it simple in the beginning so that it increases the odds of me completing it. Over the years I've had a string of projects that simply got too involved before any of the fun began. I know me.

Why would I want to turn off the rear O2 sensor?

Is there a real problem using one with the VATS active?

[cyrus_the_great]

VATs are in relation to some hardware located on the car body and harness so easier to disable it completely by hptuner .

removing the CATs core was a must for my project and rear o2s are about to check cats operation condition ...if you wanna delete them no need to have them anymore.

i say it simple you will need hptuner or something like hptuner on this project 100%.... it 's not just about VATs.

well stock engine on my ciera was 140hp only with 3speed but this one atleast 320hp now + 6speed so you guess how it feels.. how it sounds or moves the car around giving some feeling like driving a 2016 sport car.

my lfx ecm is e39 and only prolem i have until now is a strange idle adjustment which whatever i did can not change it from 680rpm ... in fact i change many things in tune but i see no effect in real world.