General Maintenance & Repairs - Car running better with O2 sensors unplugged?

I made a thread about some problems I was having before with my car. It was just not running right, the main thing I noticed was when I'd slow down or come to a stop the cars would idle very low and sound like it was going to stall. I tried a lot of different things to help the car but had no luck. I unplugged the O2 sensors just to try something else and I haven't had the problems since.
I was wondering if I should go ahead and just replace the O2 sensors or if this could mean something else.
Thanks in advance for any help.

If your car runs better with the o2 sensors unplugged your sensors are on the way out. Wouldn't hurt to replace them.

also try cleaning your MAF and IAC .

you can unplug the rear ones and it will run fine but ses light will come on you can have it tuned out

You should not unplug your front O2 sensors because they control your air fuel mix.

You should not unplug your front O2 sensors because they control your air fuel mix.


The car has other ways of compensating for that, so it's not like his engine would explode if he unplugs the front sensors.

The car has other ways of compensating for that, so it's not like his engine would explode if he unplugs the front sensors.

OK then unplug your O2 sensors and don't worry about it....LMAO.

Did you see if the problem went away if the O2 sensors were plugged in but the MAF was unplugged?

Did you see if the problem went away if the O2 sensors were plugged in but the MAF was unplugged?

I haven't tried that yet, I'll be sure to tomorrow.

What will it mean?

You should not unplug your front O2 sensors because they control your air fuel mix.

Your car will run in open loop with no 02s which is fine. Just runs rich as hell.

A dirty or bad MAF sensor will also give you a rough running engine.

Get a decent scan tool and check to see what the 02s are doing if they are switching properly and arent getting lazy. I have actually had a engine fail after running it hard for a long period of time with the 02 unplugged it leaned out and melted a piston, it was not a gm so I am sure it is a different system but I would be careful.

I haven't tried that yet, I'll be sure to tomorrow.

What will it mean?

When everything is plugged up and the car is warmed up, it'll run Closed loop. If you unplug the maf, it still runs closed (accepts input from the O2 sensors), but in speed density mode. If you unplug the O2s, it puts the bank w/ the unplugged sensor into open loop mode. So if you unplug the MAF and plug in the O2s and it runs good, that means you probably have a dirty or bad MAF. Especially if you run a K&N Filter. The oil on those things loves to fck with your MAF. Another possibility is a bad IAT Sensor.

also try cleaning your MAF and IAC .
this and replace ur o2's,and u good

Is your car throwing a SES? You can get rear simulators, or have them tuned out.

There are no rear o2's, they have been tuned out. I still haven't had a chance to plug the fronts back in and unplug the MAF. Hopefully I'll have time to do it tonight. Is there some type of test I can do on the oxygen sensors to see if they're bad without a scan tool?

Strange thing I noticed today, I plugged the o2s back in, I sat in the car and revved it up to 2500 rpm to hold it steady there. It dropped to ~2470 and then after a couple seconds went back up to ~2500 then went back down and back up every few seconds. I've ordered a scantool that should be here in a couple days, but does anyone have any ideas?

Flooding the engine with fuel can't be good.

Flooding the engine with fuel can't be good.

I don't understand, are you saying that it's flooding? Or are you talking about when I had the sensors unplugged?

when you had the sensors unplugged.

Check Fuel PSI. couldn't hurt, pump could be on its way out.

Checked the codes today. Two o2 sensor codes and map code. All of these make sense though, I had the map sensor unplugged for a while and the o2s unplugged also. I'll drive it tomorrow and see if it throws anymore.

Btw codes were p0134 and p0154. Also p0107

Finally got another pending p0134. Looks like I should go ahead and replace the O2s

I replaced both o2 sensors, all is good now. Hope this helps somebody else with a similar problem.

Thank you all for your help.

will the car run bad with the rear 02 sensors unhooked just wondering about to do headers on my 00 ss and dont have no simulators and dont have the cash for a tune right now any affects?