2obscura

I have searched the forums for common problems and fixes for this code p1133 but all results involve long tube headers. Hopefully someone can shed so light on this for me.

Truck is an 08 RCSB 4.8 with a Black Bear tune and a borla muffler turned down at the rear axle. This truck has stock exhuast manifolds.

Reoccurring code p1133, insuffesent switching of Heated o2 sensor bank 1 sensor 1 (driver side before cat)

The code showed up once a few months back in a massive rain storm, drove it until it cleared itself. Now 3 months later it throws the code weekly after I clear it with my scanner.

I have replaced the 02 sensor, inspected the exhuast system for leaks, checked the intake manifold for leaks and cleaned the ground wire and the frame where it attaches. No solution yet. Code still pops. Sometimes as much as 800 miles or no less than 40 miles after clearing it. As of today the code now reads as intermittent with no check engin light.

I have the info from freeze from data from my scanner from the last two times the code has been thrown.

Thanks in advance.

FFDP

iTrader: (2)

Hmm, not exactly sure. I had that code with headers on my car but it just went away after a little while.

I wonder if anything would change if you took the passenger side o2 sensor and swapped it with the drivers side.

The code does no harm at all, it's not emissions related really and can't effect fuel mileage. It's just a switching code that the computer wants to see in a given time when heating up I believe. If all else fails and you have this ability, just tune the code out.

RacinRust

Have you found the "cure" for this yet?

2obscura

I watche the readings from a scanner and everything appeared to be working fine. The only thing left to try was finding problems with the harness. Something causing low or inconsistent voltage. My drivers door speaker and power lock switch had gone out. Those both run through a circuit board located in the door handle which most if the interior wiring goes through one way or another. Replaced the switch and speakers a week apart, the speakers first and the code came back. Once the switch was replaced the DTC code cleared. Inconsistent voltage from those circuit seemed to have caused it. 1100 miles later still all good.

Truckshop

iTrader: (17)

Either need a PCM calibration update from gm or you have an exhaust leak when cold. We usually see this code when one of the exhaust manifold bolts break off at the rear of the head. Won't always hear it clearly.