I did a search on these two codes that my car keeps throwing.

P0420 and P1133.

P0420 - Catalyst system below efficeny Bank 1.

P1133 - Insufficent Switching Sensor 1 or Bank 1 Sensor 1.

If I have read correctly, the P0420 means my cat is bad, but I just had a new cat put in along with the downpipe I purchased from ZZP.

Also, P1133 means my rear O2 sensor is not working properly but I had it replaced when I had the new downpipe installed.

Anyone have any suggestions or has dealt with these codes before??

Thanks for the help!!

 

use hp tuners and turn them off thats what i did. It just sounds like the high flow is not as efficient as ythe computer would like to see with the stock cat

 

I would have to go w/, something was installed improperly...

 

it's gonna show that with a high flow cat man, just have someone with hp tuners turn off the CEL.

 

Perfect! I am getting an tune in the spring so that should take care of the CEL's!

Thanks for the quick answers!

 

P1133 is your primary o2. Might be in the tune, too high of a minimum pulse width maybe? Could also be a bad sensor.

Bank 1 Sensor 1 is your primary forward o2 used for fueling tho.

 

I do not have a tune yet....just the Stage II tune that GM puts on the car. I am going to be getting a proper tune in the spring.

 

Something isn't right. I would take it to the dealer and have them do warranty work if they allow it.

A switching code I find is usually a tuning problem. It could also be a bad sensor, bad wiring, an exhaust leak (would have to be fairly excessive in this case), the pcm, or if its a custom header the mounting location of the o2. I would definetly get that taken care of though.

 

I'm sticking w/ install error. Take it back to where ever you had the DP installed first. Chances are they screwed something up w/ the 02 sensor...

 

I watched them do it though when they put the new O2 sensor in. I even saw it show up with the parts delivery truck from the dealership, so I am betting it was not put in wrong. I can clear the codes with my code reader, but they eventually come back. I cleared them last night, I will see if they came on again.

Would having one older O2 sensor and a brand new one do anything?

 

No they work independent of each other. The code is not for the sensor after your cat. That one is there just to ensure the cat itself is working correctly. P1133 is for the sensor before the cat which is used to ensure proper fueling during idle and cruise.

Insuffient switching means the car isnt providing fueling properly to allow a 14.7 air fuel ratio. Its either stuck on the lean or rich side of 14.7 and isnt sweeping like it should.

 

Would disconnecting the battery for 15 minutes help?

 

i say...take em out and switch em...wait...i dont think the wires are long enough...

 

They aren't....and I can't. Kind of got a lot snow on the ground here.

 

OK!!!...same issue with the ZZP midlength

Replaced the sensor 1 and tried ohming out the harness with inconclusive results
Its down to either location of sensor or the PCM

i havent had it retuned yet but minimum pulse width would make sense

also before i installed the combo i had cat codes from a shelled converter and those have not come back after 1200 miles