Question regarding my tune and emissions passability...

[teh_mugen18]

I've got a tune on this non-boosted engine in my Integra, and its a 1990 chassis, running on obd1. I don't have to go and do my emissions for another couple months but I just was wondering about the way the shop tuned my car, or whatever. They tuned it and its running good, but with a disabled oxygen sensor. My gas mileage is so-so, but i know it could be better if i had the sensor on.
Now, i was just wondering, if it would affect me passing emissions to have the o2 hooked up or not. I asked the shop this question, and they told me that I wouldn't really have to worry about it as long as its tuned right, and that it wouldn't make too much of a difference with me getting better gas mileage. :thinking: I'm not so sure about that...but I just want to make sure i'm in the clear for passing emissions before emissions time comes.

I currently have a test pipe on the car, and whenever people ride behind me, they always complain about how bad it smells when i really start getting on it lol.... which leads me here. And before you ask "how are you going to pass emissions with a test pipe?!" im not. I'm going to swap the catalytic back in there before i go take the test.

[Vteckidd]

Car uses the o2 sensor for partial throttle gas mileage turning it off you tune the individual fuel trims rather than depending on the o2 sensor to do it automatically.

Did you have a check engine light for the o2 sensor? If so then they had to turn it off.

Can it effect your gas mileage, not really as long as it's tuned to 14.7:1 during cruise. If it wasn't then yes it will effect gas mileage and emmisions output

again a simple google search could solve all your problems not trying to be a dick but look up stoich a/f or o2 sensor. This took me 3 seconds

http://www.autofamille.com/stoichiometric-af-ratio-meter

who tuned it?

[Vteckidd]

Also you should learn what closed loop and open loop means to get a better understanding of an ecu an 02s function. Good stuff to know generally speaking

[teh_mugen18]

Car uses the o2 sensor for partial throttle gas mileage turning it off you tune the individual fuel trims rather than depending on the o2 sensor to do it automatically.

Did you have a check engine light for the o2 sensor? If so then they had to turn it off.

Can it effect your gas mileage, not really as long as it's tuned to 14.7:1 during cruise. If it wasn't then yes it will effect gas mileage and emmisions output

again a simple google search could solve all your problems not trying to be a dick but look up stoich a/f or o2 sensor. This took me 3 seconds

http://www.autofamille.com/stoichiometric-af-ratio-meter

who tuned it?


:doh:

I figured this was something specific enough that I wouldn't be able to find it on google, thats the only reason i posted here instead.

Import Experts did the tune. I really think it runs a bit rich when not at WOT though, but i dont know for sure. I only say that because I can smell the atomized fuel mix coming into the cabin a little bit when the engine is on the cooler side. And the tuner also said he usually turns them off anyways, so its one less thing to deal with during the whole tuning process.

[Vteckidd]

I wasn't being mean I was just saying search first you would be surprised how much you can gain a better understanding in general. Hopefully that article helps.

I'd they tuned it what was the a/f ratio at wot, they should have given you a graph

[teh_mugen18]

I wasn't being mean I was just saying search first you would be surprised how much you can gain a better understanding in general. Hopefully that article helps.

I'd they tuned it what was the a/f ratio at wot, they should have given you a graph


I didnt get the AFR's on the dyno graph, just the whp and wtq. The afr graph is blank.

EDIT: so, essentially, what i'm taking from your first post is that I actually indeed don't have much to worry about as far as my passing emissions...unless the car is just tuned to a very rich afr at partial throttle, in which case, i would have to have them reactivate the oxygen sensor in my ecu to make it pass (on the second try, if it fails the first time)?

[Vteckidd]

Kinda

if your o2 sensor is BAD re-enabling it won't fix the problem. Without an a/f graph you have no idea what they tuned it to. If it's 12:1 you won't pass. If it's 15:1 it won't pass.

Are you sure they "tuned" it or did they just do power pulls. How long did it take etc. If it was tuned they should provide you an a/f graph so you know where your car is tuned to. Not providing that info is not informing the customer of the job/service they performed.

They may have just forgot to put it on the sheet so I'd call them and ask for a copy with the a/f plotted

[teh_mugen18]

Kinda

if your o2 sensor is BAD re-enabling it won't fix the problem. Without an a/f graph you have no idea what they tuned it to. If it's 12:1 you won't pass. If it's 15:1 it won't pass.

Are you sure they "tuned" it or did they just do power pulls. How long did it take etc. If it was tuned they should provide you an a/f graph so you know where your car is tuned to. Not providing that info is not informing the customer of the job/service they performed.

They may have just forgot to put it on the sheet so I'd call them and ask for a copy with the a/f plotted

The oxygen sensor is brand new, it shouldnt be bad... I know that it could be though. I was prepared to have the car on the dyno for 2 hours, since thats what they quoted me. I pulled the car onto the dyno,he goot in, hooked up his laptop to my ecu, checked all my vacuum lines in the engine bay, and all my wiring, etc. and got going; he first let it idle for a couple minutes to let it come up to operating temperature, and then checked the AFR and ignition timing at idle...then he ran it and did afr checks on my low cam profile ONLY, and then ran it a few more times to get the afr's looking better...and then he started moving around my vtec crossover point, and checking the afr's at the crossover point, and in vtec as well. But they ended up taking the car off after about an hour and a half, since no more power could be pulled from it on that day.

And, can they still go back and pull my exact dyno/afr sheet, even though its been a few months since i got tuned? I dont know if its one of those things they would keep and save or not :dunno:

[Vteckidd]

I can't speak for them but mainstream and batlground (2 shops I worked for) the dyno runs are stored automatically to their winpep7 dyno files. Both shops have records over 7 years old.

If the o2 sensor was new and working I don't see any reason to turn it off, but I don't tune so Scotty or someone else should prob answer that for sure.

Did he install a wideband o2(put your car in the air and put their o2 sensor in it that's connected to the wideband)?

Sometimes if you have only one o2 they turn it off during tuning, then back on when done tuning. Sounds like you need some questions answered I'd contact them and ask for a copy of the dyno with a/f graph emailed to you so you can see how close you are to passing emissions

[teh_mugen18]

I can't speak for them but mainstream and batlground (2 shops I worked for) the dyno runs are stored automatically to their winpep7 dyno files. Both shops have records over 7 years old.

If the o2 sensor was new and working I don't see any reason to turn it off, but I don't tune so Scotty or someone else should prob answer that for sure.

Did he install a wideband o2(put your car in the air and put their o2 sensor in it that's connected to the wideband)?

Sometimes if you have only one o2 they turn it off during tuning, then back on when done tuning. Sounds like you need some questions answered I'd contact them and ask for a copy of the dyno with a/f graph emailed to you so you can see how close you are to passing emissions

Well, since Winpep7/DynoJet software was the same thing they used to tune for me, i guess it would be saved then.

and yup, wideband was connected as well. :goodjob:

[teh_mugen18]

how much did you put down????




haha, not enough... lolol... :D

i realized, recently that i also had a bad solenoid on my engine as well, soo... i replaced it, and power is MUCH smoother than it used to be. Im gonna try to re-dyno (3pulls) and see what happens with the powerband.

[Black4DrEK]

hmm....

So are you really still all motor? or did you go boost?

[teh_mugen18]

hmm....

So are you really still all motor? or did you go boost?


yeah, no boost here... probably won't be boosting this engine either. I'm saving it for the next block i get built, since i dont trust my current engine enough to do it on stock internals. I'd be fine, im sure, but i dont wanna push it anyways. LOL, heck, i was afraid of revving to 8k...I may pull it out later on, when i get the built block ready to go in and then throw some high comp pistons in there though :cheers:

[Black4DrEK]

yeah, no boost here... probably won't be boosting this engine either. I'm saving it for the next block i get built, since i dont trust my current one enough to do it on stock internals. I'd be fine, im sure, but i dont wanna push it anyways. I may pull it out later on, when i get the built block ready to go in and then throw some high comp pistons in there though :cheers:

So you went for LSV again?


high compresion for boost?

[teh_mugen18]

So you went for LSV again?


high compresion for boost?


lol, nah.... i have a second block i've been planning on having built :ninja:

The engine thats in my car currently, i was going to pull it out after i have the second block built, put in my car and turbo'd. So i could have it on the side, just in case if the boosted engine ever decided to not run anymore. lol. And while the current engine is out, it would be just sitting around(as an extra), in which case I would have plenty of time to rip it apart and rebuild it again, only with higher compression internals.

[Black4DrEK]

I see..

[scttydb411]

from what you've said you won't pass.

when i tune i shoot to keep the fuel trims low and close to stoich just in case the o2 doesn't work when it's re-enabled you'll at least get good economy in the lower load areas. even if it's flat 14.7 w/o a cat it'll fail most of the time. you should re-install the cat and re-enable the o2. the cat will clean up the emissions and the o2 will average out flipping back in forth rich/lean. it may possibly pass w/o the o2 and a cat, but based on you saying while cruising you're smelling fuel and not the best mileage i doubt it.

[teh_mugen18]

well, I'm going to go ahead and put the cat back in before I take my emissions test, for sure. I'm just wondering about whether or not I should have the sensor re-enabled or not.

[Vteckidd]

from what you've said you won't pass.

when i tune i shoot to keep the fuel trims low and close to stoich just in case the o2 doesn't work when it's re-enabled you'll at least get good economy in the lower load areas. even if it's flat 14.7 w/o a cat it'll fail most of the time. you should re-install the cat and re-enable the o2. the cat will clean up the emissions and the o2 will average out flipping back in forth rich/lean. it may possibly pass w/o the o2 and a cat, but based on you saying while cruising you're smelling fuel and not the best mileage i doubt it.

thanks for clarifying!