gentlejax2

I tried to get the vice grips around the sucker but it slipped..

back up... the nut around the O2 is rounded off so the socket is useless or more useless than it was to begin with....so

I am going to spend Sunday trying to destroy and remove the bastard by any means possible so that I do not have to remove the manifold.

I do not want to remove the mani because if I did that I would have to remove the Bonez downpipe which gave me hell for 3 weeks with leaks. now it is sealed 95% at both ends and I do not want to have to do that over. I am planning on getting some new squishy gaskets before I do it over.

so I am thinking DO anything possible to get it out before having to remove the mani. If I have to do that then I will put a header in its place when I pull it.

I just wasnt ready or had time to do more shiet to it after finally getting it all sealed up.



the car runs good but idles funny and the "CHECK ENGINE " light comes on sometimes not all the time.


SO how long can I drive it like it is before I have a problem ? the motor is fine and I know the air /fuel is off now but what are the effects of this if I cant get it out Sunday?

Kim

I dont think that the O2 sensor does any damage to your motor, its mainly used for highway speeds, or so ive been told.

My car doesnt even have an O2 sensor, idles smooth and quiet

gentlejax2

well mine seems to run just as good without it but it just about kills me to breathe around it will it is running. like a giant stink bomb. I am still running a high flow cat and have all my smog stuff for a reason. ... I have already done all the burn your eyes exhaust stuff on my last 2 cars. wasnt planning on doing it with this one.


oh yeah, gas mileage has dropped since I guess I am dumping more gas in the mix..I guess that is what is happening. I dont know anything about that stuff

rs_1101

o2 sensor only acts during cruising, helps pass smog too :-D the car has no memory ecu (assuming s4) so it just uses a preset fuel curve. if you really want to change it out, get an o2 socket from kragen or whatever you like to shop at. if your pitching the sensor, i used a big sparkplug socket.

id imagine youd just be better off spending the money on an safc.

gentlejax2

OK in post above- the nut on the o2 is rounded off because it wouldnt break loose and I was using a O2 SOCKET!! and a air ratchet.....

now, I dont have the money for a SAFC.....

anyone else

scathcart

Use a nut remover, and use some anti-seize when you put in the new one; but avoid getting any on the tip.

Kenteth

safc to lean out the curve? Whats that gain, 2mpg? O2 sensor can easily add six mpg on the highway on the STOCK computer EFI system.

safc is only superior in that you can change the curve. It having no closed-loop function does NOT make it superior, infact it makes it inferior to fuel controllers that DO have closed-loop functions.

DerangedHermit

From what I understand, that's debatable. Eh, no biggie.

rs_1101

im comparing the s4 to say... my 03 civic si. it has an ecu that adjusts fuel levels based on 02 sensor data and environmental conditions. the only thing you need an safc for on that car is radical changes in intake flow dynamics caused by cold air intakes (aem variety)

Kenteth

I'll agree with that. How could the BAC function w/o "memory." In the same sense though, I am unsure if the S4 system will "learn" to adjust fuel curves per the car's characteristic.

Example: In EFI systems that learn their own fuel curve, the curve will definately be different at sea level than it is in colorado. This is true even though air pressure is dynamic on static curves. Learned curves would still appear different. How?

Consider this:
Engine has 1000 miles on it. Its going to perform different than an engine with 150,000 on it. A learned curve is a curve that adjusts to the fatiuge and characteristics of the engine to maintain proper power and emissions.

just my 2/5 nickle

BlaCkPlaGUE

I disagree with the cruising part.. the O2 sensor is used under ALL running conditions, your car will run much richer with the O2 dead than with a new one.

Getting that o2 sensor out is gonna be a REAL pain, it will be almost impossible to get it out without removing the manifold...
in fact im not to sure how to attempt to get it out in your situation my friend...

good luck

Kenteth

Its easy if you have a removed air pump on an n/a... Just reach down with a wrench and smack. If you have the air pump or a turbo installed.. heh goodluck.

WAYNE88N/A

What I want to know is IF the S4 ECU has no memory, WHY does it have a hot 12v input, that's powered with the key OFF? Anybody?... Sounds strikingly like a memory circuit to me...

scathcart

My wideband, EGT, and tuning experience on the stock ECU says you're wrong. AFR's/EGT's are identical with or without the stock o2 sensor, save for cruising conditions. Under partial throttle and WOT, everything else is the same.

What proof do you have to back your claim?

jacobcartmill

iTrader: (6)

what are the AFR's cruising with the o2 sensor?

scathcart

Are you looking for stock, or for what I tune to?

jacobcartmill

iTrader: (6)

stock. just wondering. when i was borrowing my friends wideband i had to take my stock o2 sensor out (didnt have 2 bungs)

scathcart

Wideband didn;t have the ability to give a 0-1V simulated value?

TII or N/A?

rs_1101

the answer is simple. BAC adjusts mechanically. closing the initial set simply holds the bac from adjusting. all n/a rx7s use the same fuel curve id imagine. atmospheric pressure may or may not affect the curve in a linear fashion, but from what ive heard, mazda likes to play it safe when it comes to fuel richness/leanness.

ive got a surprise for you. my o2 readings were the same before and after i got my o2 sensor. the sensor is only used in closed loop mode from what ive observed.
thats why one forum member observed a 15hp gain with an safc unit. the car is unable to adjust its curve based on actual output of the motor, or the car would very quickly gain power through modifications.
the fact that your car is 15 years old is the reason most of us get raped on smog issues. we have to reground, resolder and rebuild and replace many parts on our cars to ensure proper operation. but the car uses the same fuelmap regardless of what brand of intake you have. look at computers from 1986. like that macintosh 2e. apparently it has the same intelligence as an ant. literally.
the ecu, is barely more than a glorified calculator.

cruising with the o2 sensor, it bounces around stoch. its called closed loop mode, and you can tell if you have an a/f guage b/c the guage will 'dance' between rich and lean. and if you listen closely you can hear the motor surging every time it does this.

wayne. you know the s4 doesnt store ecu codes. you know it doesnt store modified fuel maps, and doesnt even use the 02 sensor outside of cruising. its a dumb computer.

BlaCkPlaGUE

Well to back my claim is the smell coming out of my exhaust! With my totally dead older o2 sensor, it stunk like gasoline and emissions (no cats), when I put in the o2 it smelled just like exhaust, no more hint of gasoline. I personally saw a difference after I put it in, thats what backs my claim. Maybe the lead from the o2 sensor on your car doesn't even make it to your cpu, maybe thats why you saw no difference? im not to sure.

Tsuro

Back to the topic of removing the o2 sensor, i remember on my car (it's not an rx-7 ><) similar thing happened with a sensor (wasn't o2) and we ended up cutting off the wires, and drilling into the side, forcing a screwdriver into it and forcefully turning it. It took two goes because the sensor decided to bend a little (had it too close to the top) so we tried right up against the manifold 2nd time. Sprayed a lot of WD40 around it too.

I think the drill we used was for drilling into concrete or something cause it was a big **** as compared to your usual cordless drill

scathcart

The O2 sensor is ignored at idle. I tune these cars using some very sophisiticated, and expensive, datalogging equipment, and I build and rewire these cars all the time.
I can guarantee that the O2 sesnor is wired correctly into the ECU, and not the CPU, in each of these cases, and I can guarantee that an O2 sensor in the car or not, idle AFR's are the same.
I expect your experiences with your exhaust smell are coincidental.

scathcart

That's a damn good idea.

BlaCkPlaGUE

^my dad says that as long as you have the right tools and time, you never have to do it that way. I can personally vouch thats true with my o2 sensor experience.

anyways, scathcart, im not doubting your experience, im just telling you what I experienced when I changed mine out.

Tsuro

He did say he's willing to try anything to get it out.