31/26 mpg after O2 change
You people have widebands right? So then you should see that even in lower rpms you still get a stoich a/f ratio of 14.7 . So common sense tells you that 14.7 a/f ratio at 2.2k rpms consumes less gas than a/f of 14.7 @ 3.5k rpms. (with the same amount of throttle for both cases)
-Paul
While it may be easy to make that statement when comparing 2.2k rpm vs. 3.5k rpm, it's not as easy when comparing 2k rpm to 2.6k rpm. I've found I get better gas mileage shifting higher with lighter throttle than shifting lower with slightly more throttle. The most important thing is keeping out of boost, not necessarily keeping rpms down.
-Paul
-Paul
Evolving Member
Joined: Feb 2005
Posts: 128
Likes: 0
From: Irving,Texas
I had to replaced my o2 sensor when the stocker stripped its threads when I tried to re-use it in the new o2 housing.Autozone had a Bosch unit for me in one day for $219.Compare with Mitsu wanting up to $350 and a 3-5 day wait.I did notice a smoother idle.I don't know if the new 10.5 or o2 housing had anything to do with this.
Ummm, why are people saying they noticed better MPG's after a tune? I thought tuning was done for WOT runs only. All cars whether tuned or not, during normal driving have a/f ratios of 14.7 or very close to it. Unless I'm missing something here?
Here is my original post...
So i just installed the universal Bosch replacement front o2 sensor and first impression are pretty good actually....the idle seems to have flatten a bit compared to the OEM denso sensor based of my wideband readings and MPG wise i have gone from 11mpg to 18mpg city driving with cams, 850cc injectors, and FPEVOGreen....i cant complain 
My Short and Middle fuel trims have stayed the same (based off MitsuLogger) but my o2 trims have gone from -3/+3 to -1/+1 at idle which can explain why the idle A/F have smoothen out so much...
I must admit that this sensor plays no role in WOT driving but it does make a significant difference thus far regular city driving...i will give more feedback as time goes along....
Has anyone else replaced the sensor with positive feedback? Please chime in....
Ok...the man replaced his o2 sensor....how many of you have actually done this and experienced these results....i see alot of you that replaced the o2 housing but the fact of the matter here is that he replaced the actual o2 sensor as well....
who knows....that $330 OEM denso o2 sensor might be a piece of ish and the $70 universal bosch replacement might be a bit more accurate in reading the fuel and allowing for better fuel trim adjustments and allowing it to be a more fine tuned than the OEM was..remember, that the Bosch sensors are the ones used by those that do wideband tuning (like the zeitronix and the LC-1) although this sensor in question is in fact a narrowband sensor..lets here from those that actually replaced the OEM denso sensor with this after market Bosch sensor and let all the others see what results are provided instead of polluting this thread with "no way" or "yeah right"
I will be getting this replacement here pretty soon and see whats up....might just be worth it and be a good fuel economy mod for those tight in the pockets.....and for me in Cali at $3.49 a gallon of 91 oct....i can afford to try the $70 mod once to see if the fuel consumption increases in the long run since just one tank of gas is in the $45 range now a days...
who knows....that $330 OEM denso o2 sensor might be a piece of ish and the $70 universal bosch replacement might be a bit more accurate in reading the fuel and allowing for better fuel trim adjustments and allowing it to be a more fine tuned than the OEM was..remember, that the Bosch sensors are the ones used by those that do wideband tuning (like the zeitronix and the LC-1) although this sensor in question is in fact a narrowband sensor..lets here from those that actually replaced the OEM denso sensor with this after market Bosch sensor and let all the others see what results are provided instead of polluting this thread with "no way" or "yeah right"
I will be getting this replacement here pretty soon and see whats up....might just be worth it and be a good fuel economy mod for those tight in the pockets.....and for me in Cali at $3.49 a gallon of 91 oct....i can afford to try the $70 mod once to see if the fuel consumption increases in the long run since just one tank of gas is in the $45 range now a days...
My Short and Middle fuel trims have stayed the same (based off MitsuLogger) but my o2 trims have gone from -3/+3 to -1/+1 at idle which can explain why the idle A/F have smoothen out so much...
I must admit that this sensor plays no role in WOT driving but it does make a significant difference thus far regular city driving...i will give more feedback as time goes along....
Has anyone else replaced the sensor with positive feedback? Please chime in....
Last edited by alan678; Apr 22, 2007 at 09:20 AM.
So i just installed the universal Bosch replacement front o2 sensor and first impression are pretty good actually....the idle seems to have flatten a bit compared to the OEM denso sensor based of my wideband readings and MPG wise i have gone from 11mpg to 18mpg city driving with cams, 850cc injectors, and FPEVOGreen....i cant complain
My Short and Middle fuel trims have stayed the same (based off MitsuLogger) but my o2 trims have gone from -3/+3 to -1/+1 at idle which can explain why the idle A/F have smoothen out so much...
I must admit that this sensor plays no role in WOT driving but it does make a significant difference thus far regular city driving...i will give more feedback as time goes along....
Has anyone else replaced the sensor with positive feedback? Please chime in....
My Short and Middle fuel trims have stayed the same (based off MitsuLogger) but my o2 trims have gone from -3/+3 to -1/+1 at idle which can explain why the idle A/F have smoothen out so much...
I must admit that this sensor plays no role in WOT driving but it does make a significant difference thus far regular city driving...i will give more feedback as time goes along....
Has anyone else replaced the sensor with positive feedback? Please chime in....
While it may be easy to make that statement when comparing 2.2k rpm vs. 3.5k rpm, it's not as easy when comparing 2k rpm to 2.6k rpm. I've found I get better gas mileage shifting higher with lighter throttle than shifting lower with slightly more throttle. The most important thing is keeping out of boost, not necessarily keeping rpms down.
-Paul
-Paul
I'm running a small experiement with my own evo, I have the Zeritronix wideband setup to simulate my narrow band output. I have a 10 watt 12ohm resistor simulating the o2 heating circuit so i'm not throwing codes. I have bumped my o2 switching point slightly higher than 14.7 to 15.1 so while the car is in open loop mode it should run at the slightly leaner point. Giving it throttle obviously knocks the AFR down to more acceptable levels. I've been told that most cars can drive at AFR levels of 15.5-16.0 but i'm just not willing to push the switching point up that far.
So i just installed the universal Bosch replacement front o2 sensor and first impression are pretty good actually....the idle seems to have flatten a bit compared to the OEM denso sensor based of my wideband readings and MPG wise i have gone from 11mpg to 18mpg city driving with cams, 850cc injectors, and FPEVOGreen....i cant complain
My Short and Middle fuel trims have stayed the same (based off MitsuLogger) but my o2 trims have gone from -3/+3 to -1/+1 at idle which can explain why the idle A/F have smoothen out so much...
I must admit that this sensor plays no role in WOT driving but it does make a significant difference thus far regular city driving...i will give more feedback as time goes along....
Has anyone else replaced the sensor with positive feedback? Please chime in....
My Short and Middle fuel trims have stayed the same (based off MitsuLogger) but my o2 trims have gone from -3/+3 to -1/+1 at idle which can explain why the idle A/F have smoothen out so much...
I must admit that this sensor plays no role in WOT driving but it does make a significant difference thus far regular city driving...i will give more feedback as time goes along....
Has anyone else replaced the sensor with positive feedback? Please chime in....