Title: Get better mpg ?
Post by: Shaq on July 23, 2004, 05:34:28 PM
Post by: Shaq on July 23, 2004, 05:34:28 PM
Do you reckon this is true I am not too fussed about the mpg my car does but is this true you should replace this every 30,000 miles ? also do you think this actually improves your mpg?
"Tired of poor mileage on your RX-7? Here’s a solution. The oxygen sensor is out of sight and out of mind. On many cars, it has never been replaced. Unfortunately, O2 sensors lose accuracy with time and eventually ends up hurting gas mileage. Replacing this part every 30,000 miles will keep this from ever becoming an issue. Many have seen improvements of as much as 8mpg. Our replacement is a direct fit and saves about $100 over the Mazda unit. Buy one today and save!"
link of pic:
http://rx7.com/store/rx7/RPO2sensor.html
shaQ
"Tired of poor mileage on your RX-7? Here’s a solution. The oxygen sensor is out of sight and out of mind. On many cars, it has never been replaced. Unfortunately, O2 sensors lose accuracy with time and eventually ends up hurting gas mileage. Replacing this part every 30,000 miles will keep this from ever becoming an issue. Many have seen improvements of as much as 8mpg. Our replacement is a direct fit and saves about $100 over the Mazda unit. Buy one today and save!"
link of pic:
http://rx7.com/store/rx7/RPO2sensor.html
shaQ
Title: Get better mpg ?
Post by: Shark on July 23, 2004, 06:49:26 PM
Post by: Shark on July 23, 2004, 06:49:26 PM
Surely if the O2 sensor was faulty you\'d know about it as the engine wouldn\'t be fed properly. ??
...or am I talking out of my
...or am I talking out of my
Title: Get better mpg ?
Post by: Shaq on July 24, 2004, 07:20:46 PM
Post by: Shaq on July 24, 2004, 07:20:46 PM
mmm... not sure anyone have any other suggestions?
shaQ
shaQ
Title: Get better mpg ?
Post by: FDDreamer on July 25, 2004, 11:57:05 AM
Post by: FDDreamer on July 25, 2004, 11:57:05 AM
Think you\'re right G. If the engine was being provided with an incorrect amount of O2 (either too much OR too little) but the normal amount of fuel it wouldn\'t take long for the old 13B to let you know! :p
Unless the fuel sensor works in harmony with the O2 sensor - when the o2 decreases, for example, so does the fuel?
Would like to know, sure one of the techie guys could help, i don\'t really know what i\'m on about. But 8mpg...that\'s a 50% improvement or so, right?
Unless the fuel sensor works in harmony with the O2 sensor - when the o2 decreases, for example, so does the fuel?
Would like to know, sure one of the techie guys could help, i don\'t really know what i\'m on about. But 8mpg...that\'s a 50% improvement or so, right?
Title: Get better mpg ?
Post by: bobster on July 25, 2004, 04:53:45 PM
Post by: bobster on July 25, 2004, 04:53:45 PM
Adrian
The O2 sensor is mounted in the exhaust and basically feeds a voltage to the ECU letting it know what is happeneing with regards to fueling. i.e rich/lean.
Replacing the O2 sensor can\'t really be a bad thing because as time passes the O2 can foul up with carbon if you are running too rich, making it less sensitive. Therefore the ECU wont be gettting readings that are as accurate as they could be.
I Had to replace the O2 on my last car as I filled with 4star by accident and killed the cat... I noticed the psychological improvement in performance.;)
The O2 sensor is mounted in the exhaust and basically feeds a voltage to the ECU letting it know what is happeneing with regards to fueling. i.e rich/lean.
Replacing the O2 sensor can\'t really be a bad thing because as time passes the O2 can foul up with carbon if you are running too rich, making it less sensitive. Therefore the ECU wont be gettting readings that are as accurate as they could be.
I Had to replace the O2 on my last car as I filled with 4star by accident and killed the cat... I noticed the psychological improvement in performance.;)
Title: Get better mpg ?
Post by: paul C on July 25, 2004, 09:20:42 PM
Post by: paul C on July 25, 2004, 09:20:42 PM
Isnt the o2 sensor only used during idle ? doesnty any load on the engine cause the ecu to switch over to using other sensors on the car ? map, temp etc.
Not sure but I thaught this was the case.
Paul
Not sure but I thaught this was the case.
Paul
Title: Get better mpg ?
Post by: Shark on July 25, 2004, 10:07:13 PM
Post by: Shark on July 25, 2004, 10:07:13 PM
Had to replace the O21 sensor on the Merc that I had before the rex. Basically when that went, I was okay at speed, but at idele or in slow moving traffic it would splutter and cut out.
Huge amounts of fun in an automatic.
Once replaced everything hunky dory again so I assumed O2 sensor affects fuelling significantly so if it\'s significantly worn you\'ll know.
I guess as you say Bob, it\'ll get foulled in small steps so you won\'t necesarily notice anything till it\'s really obvious. Didn;t see it coming with the Merc, that\'s for sure.
Huge amounts of fun in an automatic.
Once replaced everything hunky dory again so I assumed O2 sensor affects fuelling significantly so if it\'s significantly worn you\'ll know.
I guess as you say Bob, it\'ll get foulled in small steps so you won\'t necesarily notice anything till it\'s really obvious. Didn;t see it coming with the Merc, that\'s for sure.
Title: Get better mpg ?
Post by: bobster on July 26, 2004, 01:42:43 AM
Post by: bobster on July 26, 2004, 01:42:43 AM
QuoteOriginally posted by paul C
Isnt the o2 sensor only used during idle ? doesnty any load on the engine cause the ecu to switch over to using other sensors on the car ? map, temp etc.
Not sure but I thaught this was the case.
Paul
Not as far as I am aware... that would be pretty pointless.
Title: Get better mpg ?
Post by: boltoa on July 26, 2004, 09:50:47 AM
Post by: boltoa on July 26, 2004, 09:50:47 AM
I think Paul is right - most cars only use closed loop lambda control (ie finding stoichimetric fuelling with a feedback loop) at low revs. Switch over to a fuelling map at high revs. This is because at high revs/load, fuelling has to be rich for to avoid overheating and detonation, so it doesn\'t care what the lambda is.
I imagine that if you do a lot of motorway miles, replacing O2 sensor might help a little, but if you drive like a normal RX7 driver (ie plenty of right foot), it won\'t really change much :).
Andrew
I imagine that if you do a lot of motorway miles, replacing O2 sensor might help a little, but if you drive like a normal RX7 driver (ie plenty of right foot), it won\'t really change much :).
Andrew
Title: Get better mpg ?
Post by: FDDreamer on July 26, 2004, 04:06:30 PM
Post by: FDDreamer on July 26, 2004, 04:06:30 PM
Blimey. Whole lot of big words flying about here! Can see the sense in both points, but would the O2 sensor not still contribute under load to assist the other parts of the system in determining the correct mixture etc?
Either way, can certainly see the sense in changing the sensor, if for no other reason that it\'s performance would degrade over time, and mean that (even if it is just a low revs) information sent to the ECU might not be as accurate as it could be.
Either way, can certainly see the sense in changing the sensor, if for no other reason that it\'s performance would degrade over time, and mean that (even if it is just a low revs) information sent to the ECU might not be as accurate as it could be.
Title: Get better mpg ?
Post by: leggysrx7 on July 26, 2004, 07:19:35 PM
Post by: leggysrx7 on July 26, 2004, 07:19:35 PM
...i\'ve had my o2 sensor replaced as well a couple of months back...
...car had an issue idling and general running pretty poor...seems it was the o2 sensor, not regulating the fuel properly...it was telling the ecu that there was more fuel needed....then vice versa.....causing the car to be ruff at idle and stalling.....
...all sorted now though!!!
Marc
...car had an issue idling and general running pretty poor...seems it was the o2 sensor, not regulating the fuel properly...it was telling the ecu that there was more fuel needed....then vice versa.....causing the car to be ruff at idle and stalling.....
...all sorted now though!!!
Marc
Title: Get better mpg ?
Post by: bobster on July 26, 2004, 07:27:59 PM
Post by: bobster on July 26, 2004, 07:27:59 PM
Might give it try then ;)
Title: Get better mpg ?
Post by: leggysrx7 on July 26, 2004, 07:32:37 PM
Post by: leggysrx7 on July 26, 2004, 07:32:37 PM
...might be worth a try, certainly solved my idling/stalling issues...hows your car running??havent heard anything from rich/robbie...
...all quiet, which can\'t be a good sign :(
..new pivot controller arrives this week for the sleepy headlight effect..phoning Marc at the garage tomorrow to organise the dreaded MOT....
Marc
...all quiet, which can\'t be a good sign :(
..new pivot controller arrives this week for the sleepy headlight effect..phoning Marc at the garage tomorrow to organise the dreaded MOT....
Marc
Title: Get better mpg ?
Post by: bobster on July 26, 2004, 09:27:31 PM
Post by: bobster on July 26, 2004, 09:27:31 PM
Running okay at the moment. Got a RR day coming up so we will find out
Robbies is dead and I don\'t really know what is happening with Rich..... saw his FD at the Garage a week or two ago.... more Engine problems I think.
Good luck with the MOT.
Robbies is dead and I don\'t really know what is happening with Rich..... saw his FD at the Garage a week or two ago.... more Engine problems I think.
Good luck with the MOT.