O2 doin funny things

[eaglescout526]

Anyone had the O2 do funny things to drivability? I could be chasing nothing here but the REM shows me when in closed loop, it rarely switches to rich and more or less stays lean. Then it jumps into open loop and stays stuck on lean. Isnt Renix supposed to swap to rich when in open loop? 

Anyways I can basically restart my XJ, drive for a bit and then back to driving issues like I am running out of fuel.

 

Anyone have anything similar? I will swap the O2 out but never seen this be an issue. I have seen it to where it warms up and just decides to not work at all but still do the rich lean swap like it should. But then it would go into open loop and be able to drive fine.

[watchamakalit]

Fuel pressure ok?  Clogged filter causing a lean condition   Maybe just a faulty O2. I had a perpetual rich condition in mine when my O2 quit.

[75sv1]

I did on a Ford Tempo. I would be doing say 65 on the highway, then I'd have the pedal to the floor struggling to do 55. Then back to 'normal'. I changed the O2, and things were go. Well, for a Tempo. 

[eaglescout526]

6 hours ago, watchamakalit said:

Fuel pressure ok?  Clogged filter causing a lean condition   Maybe just a faulty O2. I had a perpetual rich condition in mine when my O2 quit.

As far as I can tell without trying to gather some adaptors and a gauge to put on the “rail”, it seems fine. I did have the issue of the fuel pump failing but reading the REM showed me the O2 switch slowly and then stop switching all together. I think at this point I’ve confirmed it to be the O2

[watchamakalit]

5 hours ago, eaglescout526 said:

As far as I can tell without trying to gather some adaptors and a gauge to put on the “rail”, it seems fine. I did have the issue of the fuel pump failing but reading the REM showed me the O2 switch slowly and then stop switching all together. I think at this point I’ve confirmed it to be the O2

Sounds like O2 sensor to me  I forgot the 2.5 doesn't have a Schrader valve to check fuel pressure.

[eaglescout526]

12 minutes ago, watchamakalit said:

Sounds like O2 sensor to me  I forgot the 2.5 doesn't have a Schrader valve to check fuel pressure.

It’s exactly what I’m thinking. What pisses me off about all this is the sensor is new, NOS but it’s barely seen any miles. 
Yup! Still been trying to figure out how to put a gauge on either but it’s been a bottom of the list thing. 

[pizzaman09]

When I bought my truck I put a Bosch O2 sensor in, and it did funny stuff like that.  I had blindly chosen Bosch as it was what I was familiar with as the brand of choice on the 90s BMWs I drive.  Apparently it wasn't the right choice, I put in an NTK and all was well, the sensor is super responsive according to my REM and it runs smoothly all of the time.  With the Bosch sensor it out go lean for long periods of time and have rough lean idle.

[watchamakalit]

1 hour ago, eaglescout526 said:

It’s exactly what I’m thinking. What pisses me off about all this is the sensor is new, NOS but it’s barely seen any miles. 
Yup! Still been trying to figure out how to put a gauge on either but it’s been a bottom of the list thing. 

NOS still means "new OLD stock". Maybe it's not service hours that kills them aom much as just age.

[eaglescout526]

19 minutes ago, pizzaman09 said:

lean for long periods of time and have rough lean idle.

Sounds similar to my issue. Very similar. But baffles me as on my MJ, it would go into closed loop, make driving really weird like almost kill the engine weird and then go into open loop and stay rich just to keep going. 
 

14 minutes ago, watchamakalit said:

NOS still means "new OLD stock". Maybe it's not service hours that kills them aom much as just age.

That’s my initial thought as well. Sucks but I guess I’ll be burning through what I have left faster. 

[pizzaman09]

Well, on my parents 97 Grand Cherokee with the 4.0L, it used to stumble something awful about 1 minute after starting it, about the time you got to the end of the driveway.  That one the issue was the combo of a bad O2 sensor and a cracked exhaust header.