1991 o2 sensor/upgrading headers issue
 

SOLVED !!!My current car has straight exaust w original exhaust manfolds/no cats. I noticed the sensors near the cat converter are just dangling and not installed right now. I never noticed any driving issues. I am waiting on my headers to get back from being dipped in coating and I was going to locate the current sensor from the driver side manifold to the exhaust flange when i install the headers. What should I do the with the other sensors that are just laying there right now? Thank you Also does anyone know what size weld bungs should i get? I was looking at these but want to make sure it will fit https://www.summitracing.com/parts/v...FVmewAodQOUHtw

I think you need to recheck. Do you have a 91? If so, I don't think there is more than 1 O2 sensor.

I would think with no 02 sensor hooked up, you would be running in open loop all the time.

With the way he puts it about the original sensor near the driver side manifold, I think the others are something else

i think your right however, I just went to check out the driver side and i followed the cable back to nothing, it was cut or burned off at somepoint, so its not been operational. There was nothing that told me the car was running poor or anything like that so I guess when I put the new headers on I wont even worry about sensor.

If you want to run in open loop with the CEL bulb removed, sure

Does that cause any issues?

Of course it does. If you don't know when the ECM is showing a problem because the light is on, how do you know when to fix it before it blows? Also how do think the ECM will go into closed loop and adjust the fuel air ratio?

Before whaqt blows? To me i believe the taking this off created no problems, none of the emissions are hooked up. so nothoing that i could tell would blow up. Worse case secerio I get the car dynoed to and tuend. Without california we wouodnt have to deal with emmissions, that state is a meanace, thank got we dont beleive in them and can trash our emssions. I cam going to put the headers one and work on fuel to air ratio. Thjanks for your adice, your always quick to help.

How will you know if the engine is running too lean? It will throw a code and turn on the light but the light is already on so you won't know without scanning. Will you know if the knock sensor is working? Bottom line is you don't know something is wrong until it breaks. I have no EGR or AIR myself and if you believe I give even less than a rats ass or whatever has the smallest ass, about emissions, I have this bridge to sell you. One owner, slightly used and well maintained. Right next to my Oceanfront property in the desert. I only spent money on a CAT because it muffled the noise

Even if you get it dyno tuned, it cannot make adjustments properly, if at all. It can only go off pre-programmed tables. I look at the program created by the dyno as a baseline where it can go richer or leaner or more or less timing or raise or lower the idle speed, etc. Without the O2 sensor, the ECM cannot monitor anything and make adjustments so it might dump fuel because the program calls for it without being able to take other things into consideration. This is why I sold the wife's machine for one a year newer. Because it had EFI. Everything else was the same. That means I can go up riding at 10000 feet one day and down to sea level the next WITHOUT rejetting.

sorry i didnt mean to offend you about my emissions rant. i understand the concept of it and why its needed. I just let my frustrations get the best of me. When i switched to fuel injected from my carb muscle cars, I assumed i would be plugging in my laptop to test and make changes to fuel, air, etc. I was way off, but I havent given up, I am just trying to learn from you and the rest. I apologize.

I'm not offended.

If you want to plug in and make changes you are going to have to learn a lot more and practice on a dyno to see what your changes have done. Besides it isn't necessarily unless you make major changes to the motor.

One of the plugs that was hanging, I found that it goes into the lower part of the engine, probably for oil gauge. I dropped off my headers today to have them ceramic and I started pulling my sparkplugs out and the plugs are covered in black soot, I looked it up and it says my motor is out of tune. I started out just needing to fix damage to my bumper and hood and since my brothers 1975 is nearing completion, it just kills me that he will have a faster car than me, I tried to buy back my mustang but the gentelmen already sold it or I wouldnt bother trying to modify my vette. I added a picture of my smog pump delete pulley, and the second photo you can see my fathers 1973 we have finished the frame, sanded, getting ready to put motor and interior.
https://cimg7.ibsrv.net/gimg/www.cor...10f8515431.jpg
https://cimg9.ibsrv.net/gimg/www.cor...a822c93de0.jpg

We can GUESS it is out of tune at midrange but with the computer, we don't know for sure where exactly. Plug reading was fine for my old Jetskis. Put fresh plugs, go for a WOT run and read them. Problem is the ECM is making changes all over the board and we simply will be hard pressed to nail it all down.

aklim, I am needing to drain my old gas, im wondering if i remove the fuel filter, could I turn the key on and would the fuel pump pump the gas out where I can just catch it??

If it could, you'd be pissed. It is a safety feature. 2 seconds of prime time and the pump is off till the ECM detects ignition pulse. You can bypass it by finding the pump wire on the ALDL, I think. Or, I would give racetronix a peek. They have a kit. You buy it and have a gasket, SS bolts to replace the screws that hold the inlet to the tank in and a piece of hose to replace the pulsator with. Of course, when you take the inlet out, you can access the tank fully. A win for the fuel system and you suck all the old gas and whatever crud is in the tank

I found out where the other end of the cut wire for my o/2 sensor is. I just got my headers back from being ceramic coated, so I am going to fix this wire and add that sensor to my new headers, hopefully that will fix my problem of fuel not being burned out. sadly a lot of my sensors that plug into the motor have broken connectors because they have no way of snapping on, they just plug in and the slightest pull will out the sensor.