Thread: Stumped with p1133 and p0137

Hello all,

I've been having troubles with these codes for a while. P0137 (Oxygen o2 Sensor Circuit Low Voltage (Bank 1, Sensor 2) and P1133 (HO2S Insufficient Switching Sensor 1) have been giving me a hard time for a while now. I have replaced the Front o2 Sensor Twice (deco) since I have put the headers in. I am almost positive that the wiring for the o2 Is fine. It has a homemade extension and then the zzp extension going to the sensor. All connections are good and the wires look good. I was getting horrible gas mileage lately and I just replaced the front o2 again and now the mileage is up and normal (almost 28 on the highway going 60-70). I have to take the car to school tomorrow (216 miles) and want to make sure that I'm safe. I've read that sometimes headers throw the p1133 code in general and I'm looking into getting a tune from reptile and getting it tuned out. (There is an intense pcm in my car now and i've had it there since I bought it). My question is, do you guys think p0137 is getting thrown because of p1133? I have a denso rear o2 sitting in the garage and might throw it on today to see if that helps. Any other ideas on this whole code deal?


Thanks a lot,

Chris

this code looks to point to the post cat o2 http://www.obd-codes.com/p0137


the other one says the upstream sensor, http://engine-codes.com/p1133_chevrolet.html

does one being bad effect the other one? Should I change the rear o2? Code tuned out a good idea?

thats a code for each, they do their own things. if one code triggers the other it will say it in the links i posted.

1133 is common problem with header install... Most remove the code reporting in tune. Otherwise, relocating the O2 sensor location is the only option that'll work. Some have drilled a bung into the rear header for the O2, but then you're only sniffing one side of the engine, lol... Pick your poison! There's many a thread on the subject : )

Little update, Ran the car for 300 miles after I replaced the rear o2 Sensor. Still nothing so so far so good. If the p1133 code comes back, be ready reptile.

P1133 is sometimes just caused by headers. Also leaky headers will cause it. A lot of guys relocate the front O2 to the crossover and have good luck with that. Or just turn the code off with hptuners

Still so far so good since I changed the rear o2. I'm assuming no news is good news. Car still just hasn't been running great. Doesn't seem to have the power it used to lol.

As of now, I haven't gotten the code since