Check engine light on

Last week the check engine light illuminated. I scanned and Code P1133 came up. I replaced the forward O2 sensor (Denso 234-4339). Cleared the code. I drove twenty miles the next day without any problem; however, yesterday the check engine light came back on and the Code P1133 came up again when I scanned last night.
What else could be causing the code or what else should I check?

Thank you for the response. I will apply the dielectric grease at the O2 connection; although I am not looking forward to taking the electric connection apart again, as it is located between the transmission housing and engine! It was not a pleasant experience. Once I finally got it apart, it took two minutes to exchange the sensor. Thank you very much.

I was thinking about that as well.

I am a contractor working in kuwait and have a fleet of 9 2008 Trailblazers. We constantly have the Check Engine light coming on, but is mainly from loose gas caps. I however have one that has now twice been to the shop for when you take off in the morning when its cold, if you accelerate rather hard it will almost shut off, the check engine light comes on and the engine will not rev over about 2500 RPMs. You can pull over, unhook the negative battery terminal for about 5 minutes, get back in and it runs fine. Everytime we take it to the shop due to the language barrier betweent us, its hard to explain or figure out what they done, but undoubtably they are not fixing the problem. I was wondering if it could be a misfire problem that is causing it to not rev after the check engine light comes on.

Enter your question.I have a 2008 chevy trail blazer and it is recently giving me problems. It does a little****** thing going down the road and the engine light comes on briefly and then shuts off and runs smoothly. Intermittantly.

I don't know the code yet. My husband has to get a new code reader.

Ok thanks

This morning the check engine light illuminated on the dash.
I scanned the vehicle with my OBD II reader. To my surprise three codes came up:
CO455: which indicates steering wheel angle sensor.

CO131: which indicates anti-lock brake traction control system, pressure switch malfunction.

P1133: which indicates O2 sensor bank 1 sensor1. The issue with this code is that it came up in April of this year. I replaced the O2 sensor. It was fine for two months then it came up again. I replaced the O2 sensor again in June thinking the first O2 sensor was defective. It was fine until I scanned today when the check engine light came on.

Please help me to resolve these three code issues. Thank you.

Thank you for your reply.
The AC-Delco would be better than the Denso O2 senor that I installed? When I replaced the previous O2 sensor, there were no visible contaminants. Is there anything else you could suggest that I check as well?
Do you have any repair information help regarding the Steering Wheel Angle Sensor ( C0455) or the Anti-lock Brake traction Control System Pressure Switch (C0131) codes?
Thank you.

After researching out names of mechanics that I would be able to trust for proper diagnosis, I brought my TBSS in yesterday. The P1133 code was coming up because of a loose connection at a harness/connector from where the electrical connection to the O2 sensor originates. The electrical connection at the O2 sensor was fine; however, at the point where the wires originate was loose. Apparently, this was located up over the transmission in an area that was difficult to access as it was a poor design/location. So, as of now, no more check engine light. I hope my post will help other people that may experience the same frustrations as I did. Another strange occurrence was that the codes for the steering wheel sensor, anti-lock brake pressure switch and "stabiltrak" did not show up when the vehicle was scanned at the mechanic. So, either the scan tool at the auto parts store was inaccurate or somehow this loose connection cause other codes to pop up.
I greatly appreciated the information from HMAC300 and OBXAUTOMEDIC. Thank you!