Catalyst Efficiency Code

[XxNovaSS1971xX]

Last week my engine light came on. I had Auto Zone read it. The codes read Catalyst Efficiency low bank. Now, I've had this code come on a few weeks ago and just had midas erase it when they installed a new 02 sensor. I was told that since I have a new Magna Flow exhaust, Y-pipe/Cat - being one big piece, on down to the muffler, that I'd have to have my PCM reprogrammed for it since it's a performance exhaust and late model Camaros always throw this code. Is this true? If so, what exactly do I need to do or go to get it done? Has anyone had this problem before?

Thanks a million!

[silverbird02]

Re: Catalyst Efficiency Code

i had that prob and i had it for awhile i did changed the O2 sensor and nothing but one day it just went away i changed my cat for a bigger one maybe thats wat did it but im not to sure i have magnaflow cat 2.2 and catback 2.5...everything is 2.5

[XxNovaSS1971xX]

Re: Catalyst Efficiency Code

So, you changed the sensor first or the magna flow cat? I'm not sure what size mine is. It was the only magna flow direct fit that Jegs carries, or carried at the time. What do you suggest I do?

[g9m1c]

Re: Catalyst Efficiency Code

i get this code all the time but its because i took my cat out when i did my exhaust. this code comes up when youve deleted the cat or have a good flowing one. it doesnt hurt anything by the code coming up its just really annoying for that light to be on 24/7. what year is your car?

[bwkmaro]

Re: Catalyst Efficiency Code

i got the same prob u can get rid of it by a o2 sensor bypass there like 40$ from zz its the rear sensor sending the code but the rear sensor doesnt control any type of fuel to air ratio so with or with out the code it doesnt hurt anything. i got it when i got my high flow cat on too but idc about my light being on so i just leave it

[g9m1c]

Re: Catalyst Efficiency Code

i got the same prob u can get rid of it by a o2 sensor bypass there like 40$ from zz its the rear sensor sending the code but the rear sensor doesnt control any type of fuel to air ratio so with or with out the code it doesnt hurt anything. i got it when i got my high flow cat on too but idc about my light being on so i just leave it

was just gonna mention that 02 emulator..I cant use it on my car though its a 96 :mad:

[bwkmaro]

Re: Catalyst Efficiency Code

oh my bad forgot about that ok this is what u do then get a spark plug non-fouler and put it on the o2 sensor itll space it out and that should fix it did that with my 1996 jimmy with no cat whatso ever

[g9m1c]

Re: Catalyst Efficiency Code

oh my bad forgot about that ok this is what u do then get a spark plug non-fouler and put it on the o2 sensor itll space it out and that should fix it did that with my 1996 jimmy with no cat whatso ever

I might just have to try that. I have a scanner but its annoying clearing the code all the time.

[XxNovaSS1971xX]

Re: Catalyst Efficiency Code

I know this whole thread is old, someone mentioned buying an 02 sensor bypass.... But from where, exactly???? I found it once on here months ago, but couldn't get it at the time. I'm ready to get it now.....

[crazytrain65]

Re: Catalyst Efficiency Code

https://www.zzperformance.com/grand_...=967&catid=107
dead thread ftw!