O2 sensors - cats

[Northpole]

I could not find the answer, I hope someone can help....

We did remove all 3 cats on my LSC 1995, and mounted some nice Raptors mufflers, great sound and hopefully better fuel eco and perhaps a few hp? We put the O2 sensors back in the same place as before, just now on new pipe, no cats. Note this car only has 2 O2 in front of the cats (thanks Chris2523.
When driving from the garage everything was just fine, BUT after few miles, the "Check Engine" light came on
The engine is fine.
After 1 hour at home I did start the engine again, and no "Check Engine" light. I went for a short drive and after 3 minutes drive it came on again... I stopped the engine for few sec and started again, no light, then after 2-3 min drive it came again, etc...
- I have not yet found a error code for this, but will write it here when I have, but again it could be difficult to do as the error only occurs after driving for 3 min...
- Anyone here have an idea what this could be?

I did the same thing on my Audi TT few years ago, I remember we moved the O2 sensors a little bit from the pipe until it "fooled" the computer. Can we do the same here, will it work?

Will this error message have any affect on the fuel consumption? I presume the engine will be fine even this light is on?

Well, this is getting more and more strange...I did get the codes:

177:Oxygen sensor not switching - system is or was lean - Single, Right or Rear HO2S - Fuel control
172:Oxygen sensor not switching - system was rich Left or Front HO2S - Fuel control
332: EGR did not open/respond during test or if memory code, did not open intermittantly - EVR or PFE

Any help on this GREATLY appreciated !

 

[NHRedneck]

because you removed the cats, the rear 02 sensors are not seeing the air changing as it should change when it goes thru the cats. the front pair of o2's is used for fuel control (chages are made in the fuel system to either lean or richen the engine) as long as you dont care about emissions testing, then driving the car should be just fine. the codes come up after 2-3 mins of driving, b/c when the engine is cold the engine is running purely on program from the computer and ignores adaptive changes, once the engine starts warming up it starts watching the front o2's..

 

[chris2523]

because you removed the cats, the rear 02 sensors are not seeing the air changing as it should change when it goes thru the cats. the front pair of o2's is used for fuel control (chages are made in the fuel system to either lean or richen the engine) as long as you dont care about emissions testing, then driving the car should be just fine. the codes come up after 2-3 mins of driving, b/c when the engine is cold the engine is running purely on program from the computer and ignores adaptive changes, once the engine starts warming up it starts watching the front o2's..

1995 is OBD1. 96 and and up is OBD2. he doesnt have any rear o2 sensors.

 

[Northpole]

Anyone tried to move the O2 sensors away from the pipe?

OR

How important are these O2 anyway?

Cant I just put a resistance between the wires?
- if so, does anyone know how many Ohm (Ω) I should use for each sensor i.e. 2 wires?

 

[NHRedneck]

the o2's are very important, since your car only has o2's in front of the cats, those are the ones that determine how much rich or lean the car is running. did you space the o2's the same distance away from the eninge as they were originally?

 

[Northpole]

the o2's are very important, since your car only has o2's in front of the cats, those are the ones that determine how much rich or lean the car is running. did you space the o2's the same distance away from the eninge as they were originally?

Thanks.
We did not move or touch the sensors at all, so yes they have exactly the same distance. How ever we did not connect the EGR pipe again, just blocked it. Could that cause this reading and the CEL ?