How to run E85 on stock 86 BRZ FRS with OFT tune

[nelsonzep]

https://drive.google.com/folderview?...00&usp=sharing

this is a link to the tune file i was running and a couple of test data logs all on e85 with out front o2 sensor spacer

[nelsonzep]

could it be the memory stored? i read someone had the same problems with the p0171 code errors and he took his battery out and charged it and then no more problem, i had some problems with p0171 before i tuned could resetting the ecu by disconnecting the battery possibly fix this? and then i just reflash the tune?

[steve99]

Originally Posted by nelsonzep

could it be the memory stored? i read someone had the same problems with the p0171 code errors and he took his battery out and charged it and then no more problem, i had some problems with p0171 before i tuned could resetting the ecu by disconnecting the battery possibly fix this? and then i just reflash the tune?

Each time you flash a tune the ecu is fully reset and all DTC codes cleared same as disconnecting battery



"i had some problems with p0171 before i tuned"

Bingo !! their is the cause, you should not get that code unless you have a problem

If you had that code before tuning the car their is a hardware problem

ie air leak intake/exhaust
bad or dirty/oily maf sensor
bad 02 sensor (will be the front o2)
Bad wiring or some other issue
Could even be a crook battery dying batterys can cause all sorts of weird issue's check battery connection earths ect.

did you have to force o2 sensors into new header they are easily damaged, they should screw in by hand then just tighten down to required torque.
Often you have to run a thread tap/chaser through new header 02 bungs to clean them up,

are the sensors in all the way so the ring is flush with header else they leak.

[nelsonzep]

well before i tuned i had catless tomei uel headers which i assumed the oft would correct? and i assume the code error was only happening because of the removed cats?

[nelsonzep]

also what can i use to clean the o2 sensor? i can wipe of the outside of them easy but can i use maf cleaner to spray into it or what should i use?

[steve99]

Originally Posted by nelsonzep

well before i tuned i had catless tomei uel headers which i assumed the oft would correct? and i assume the code error was only happening because of the removed cats?

DTC for cat efficiency is P0420

The one you saw P0171 is related to a fueling problem ie runnig so lean that the limit of the ECU fuel trim compensation is being reached

[steve99]

Originally Posted by nelsonzep

also what can i use to clean the o2 sensor? i can wipe of the outside of them easy but can i use maf cleaner to spray into it or what should i use?

If they have been contaminated or damaged then the 02 sensor will need replacement.

The Front 02 sensor is use for AFR ,

I dont like recommending that people replace expensive parts like o2 sensors , its a likely cause of you problem but i cannot be 100%.

It might be just leaking as the threads are damaged or not screw in all the way.

Suggest it may be worth taking car to a shop and get them to check unless you want to take a punt on it being the 02 sensor.

[nelsonzep]

alright then it might be leaking headers so i will go under right now and check because the code happened after replacing headers. but the code for running lean went away after a week or so and then the code for running rich popped up? before i switched to oft tune what could the running rich mean?

[steve99]

Originally Posted by nelsonzep

alright then it might be leaking headers so i will go under right now and check because the code happened after replacing headers. but the code for running lean went away after a week or so and then the code for running rich popped up? before i switched to oft tune what could the running rich mean?

With catless header even untuned the only code you should see is P0420 primary cat efficiency.

Any other code that pops up indicated a problem somewhere.

A leak or damaged 02 sensor will throw of fueling the ecu will try and compensate for what it thinks is a lean condition by adding heaps of fuel which then makes the engine run rich. It all likely related to same problem, air leaks and/or damaged 02 or maf sensors.

but since you have changed header its likely a leak or damaged sensor.

check the sensors are plugged in correctly grey plug to grey socket, black plug to black socket.

[nelsonzep]

well i know when i checked the o2s2 voltage it always read zero is this the o2 sensor voltage?

[steve99]

Originally Posted by nelsonzep

well i know when i checked the o2s2 voltage it always read zero is this the o2 sensor voltage?

The 02 sensor voltage should not be zero all the time, but it possible its a logging issue on oft, unlikely though. If you know someone with a another 86/frs/86 have a look at their 02 volts to confirm logging working.

[Texas2016Frs]

Originally Posted by steve99

Are the fuel trims always positive or always negitive
is this you first tank of e85

if they are always negitive it the tune compensating for low e% ie high petrol.
the trims will be close to zero near e70 ot their abouts

as the e% varies with e85 the fuel trims will wander to compensate. as no flex fuel sensor ,
looks ok

you rearly need to go back to petrol and then look at you fuel trims and if they were still 10% or so do maf scaling when on petrol ( second tank )

the afr at cruise idle will be in 14 as you see but under load it should be in 12 to 13, and high rpm high load low 12 maybe high 11.

the o2 sensor doesnt know your on e85 so its reading ok as its just calibrated to read petrol stoich 14.7


what were you fuel trims like on petrol ? not unusual to see 5 to 8% on petrol on a non scaled maf

My Stft is .78 and my ltft:is -7.04 at idle after about 15 miles of driving under 3.5k is this okay?

[Texas2016Frs]

Originally Posted by Texas2016Frs

My Stft is .78 and my ltft:is -7.04 at idle after about 15 miles of driving under 3.5k is this okay?

Also at wot ltft is -11.71 constantly a little worried by that, I filled up with 11.9 gallons of e"85" so I still had 1 gallon left should I be concerned?

[steve99]

Originally Posted by Texas2016Frs

Also at wot ltft is -11.71 constantly a little worried by that, I filled up with 11.9 gallons of e"85" so I still had 1 gallon left should I be concerned?

dont worry about stft it varies widly with throttle and load

ltft is the one to watch and the actual afr

if you have a low e% due residual petrol ltft will trend negitive but as long as afr at wot is mid to low 12 its ok

midrange mid throttle afr arround 13 or high 12

cruising and idle afr arround 14 to 14.7

on your next tank it will likely be less negitive ltft