how do i read narrow band o2 voltages? i have an rtek 2.0 so i can see the voltages but what do they mean? how can i tell when im near stoich?

i know there really **** but i need to make due with it till i get a wideband.

 

A car with a disabled airpump or ACV....................will read about 0.8 at idle which is RICH.

A normal reading at idle is 0.7/0.8 and not to be worried about that and don't try to lean it out. Normal.

Lean would be in the 0.1 to 0,4.

ECU going in to closed loop while driving above 1700 rpm would show a rapidly changing reading above and below 0.4. Hard to read since it will move so fast up and down.

 

So basically, don't try to tune w/ a narrowband because unless you are idling or in closed loop its not giving u any useful information.

Get a wideband before you do something you regret.

 

ok makes sense. so its not just the really bad accuracy but the closed loop makes it imposable to tune with.

are aem widebands good i like the way they look but iv heard there a bit slower to respond is it really bad should i consider something else?

 

that is kind of the point of closed loop, you dont NEED to tune there, because the O2 sensor is doing it for you.

to tune in that region you actually need to disable closed loop.

 

so is it a bad idea to tune there? wouldnt you be able to achieve better power by tuning there? so whats the real point to a wideband it cant only be just for under 1700rpm.

and if it is a good i idea to tune there then how do you disable closed loop?

 

Good tuners can use the narrowband just fine. The trick is that you need to know what you are doing because there is more to tuning than trying to match a number that you read on the internet. This also applies to wideband gauges, but they are a little easier for a novice to use because they are more accurate and less affected by temperature changes. Also, O2 sensors are intended for tuning the engine for idle and cruise rather than for performance. Contrary to what the wideband gauge vendors advertise, the wideband gauge will not magically turn a novice into a professional tuner. If you don't know what you are doing, then I recommend that you either have a professional tune your engine or that you take a tuning course at your local tech school. Your local professional tuner will have his own tuning equipment, so there should be nothing extra for you to buy other than his labor. Tuning is not something that you can learn well by reading a book or internet forums. Experimenting on your expensive engine isn't such a great idea IMO.

 

lol my "expensive" engine isnt that expensive i got it for 600 in and done its just a stock s4 keg with s5 intakes. it has a bit of the 3800 rpm lag but i tried compensating by adding 5.1% more fuel at that rpm(over kill) but now it pulls like a mother there. so im just thinking that theres more to be had and that i just dont want to lean out and blow.

 

i suggest doing a little more reading on engine tuning. there is a lot of info on this site too, although it can be hard to find.

basically the car is only in closed loop between 1200-3500rpm and PART THROTTLE. over a certain throttle position and over 3500rpm it goes back into open loop again.

if you go say to foxed.ca and start reading manuals, you'll find that mazda breaks the ecu map into "ZONES" so there is an idle zone, a cruise zone (closed loop, 1500-3500rpm, part throttle), decel zone, and a high load zone. each "zone" is optimized for a different thing. the accel zone, is optimized for power, the cruise zone is optimized for low emissions and mileage.

i don't know how to disable the 02 feedback without unplugging it. it might be in the Rtek software

 

 

lol, the red curve is scary....