2001 Tahoe cats won’t initialize

[TheEnder53]

Hello everyone.

I own a 01 Tahoe 5.3. When I bought it it had a code for the cats (P0157.)

I replaced the bank 2 sensor 2 oxygen sensor, and I could absolutely never get the cats to initialize no matter what i do. I have been at this for 3 months as i need to have it smogged in order for a title transfer.

After the battery died once, after a few days P0157 came back as a pending code with no CEL. I cleared it and it hasn’t come back yet. Cats still won’t initialize. Any help??? There are no other codes and she runs and drives like she just got off the showroom floor.

 

[Fless]

I'm not sure what you mean by cats initializing. The code you have relates to the downstream sensor's activity, or lack thereof.

What brand sensor did you install?

You could swap that sensor with the other downstream O2 sensor (right to left, and left to right) to see if the issue moves to bank 1.

 

[Doubeleive]

Hello everyone.

I own a 01 Tahoe 5.3. When I bought it it had a code for the cats (P0157.)

I replaced the bank 2 sensor 2 oxygen sensor, and I could absolutely never get the cats to initialize no matter what i do. I have been at this for 3 months as i need to have it smogged in order for a title transfer.

After the battery died once, after a few days P0157 came back as a pending code with no CEL. I cleared it and it hasn’t come back yet. Cats still won’t initialize. Any help??? There are no other codes and she runs and drives like she just got off the showroom floor.

drive it for an hour at 55mph, either it will set or throw the code again on a key cycle
p0157 is low voltage on bank 2 sensor 2 (passenger side after the cat)
there is no such thing as "initializing a cat" you are using a incorrect term that came from who knows where..........
so go drive somewhere for 30 minutes, turn around and drive back.

 

[TheEnder53]

I'm not sure what you mean by cats initializing. The code you have relates to the downstream sensor's activity, or lack thereof.

What brand sensor did you install?

You could swap that sensor with the other downstream O2 sensor (right to left, and left to right) to see if the issue moves to bank 1.

The emission monitors for the cats would not initialize.

I used a OEM ACDelco sensor. I will try driving at 55mph for an hour once i get back to CA. Currently in TX for a funeral.

 

[Doubeleive]

The emission monitors for the cats would not initialize.

I used a OEM ACDelco sensor. I will try driving at 55mph for an hour once i get back to CA. Currently in TX for a funeral.

Not initializing would mean the system doesn't even see the sensor, the 02 sensor reads temperature data and either passes and shows ready (normal) or fails and gives a obd code such as a lean condition.
If the code reader shows not ready that means just that it's not ready, and it's still in test mode. Anytime the battery is disconnected or the sensor is unplugged it will go into test mode again. There is nothing to initialize..... Although I guess you could it that but it's not a common term for a 02 sensor. It's either ready or not ready. That's what you're code reader will show ready green or not ready red/blinking. Same on a smog test if you take it in not set yet they will tell you "it's not ready"

 

[Fless]

You may want to see about getting a graphing scanner on it and see what the O2 sensor activity is like. Lots of YouTube videos about doing that.

 

[TheEnder53]

Fixed. Took it on a 10 minute drive @ 55 and they initialized almost immediately.

 

[Fless]

Fixed. Took it on a 10 minute drive @ 55 and they initialized almost immediately.

The system was already initialized. If you'd taken that to a mechanic and used the "initialized" term they probably would have looked at you funny. But glad you got the monitor to be ready.

 

[TheEnder53]

She ain’t happy anymore. If im easy on the truck, the code won’t set, but if i beat on her, it sets. I will look at it more.