Recently I was getting P1171 and P1174. I was also getting P0134 (O2 sensor circuit not activity detected bank 1 sensor 1.

I was the bank 1 upstream sensor.

Your readings should not be static at 0.12 volts. They should be constantly adjusting.

See picture of healthy upstream sensors just looking at the voltage.

Note: disregard the engine temp. That was before I knew of the In-Line thermostat mod.

 

Thanks for all the help guys. I will send some pictures of the live data when I get the chance so yall can look over it. Im assuming its the 02's as its running normally without issue besides the CEL with the two codes. Also the maf is running about 13.25- 15 kg/h at Idle and people on the forum say it should be about 20 At idle, Do you think that it could also be an issue?

 

The probability that both O2 sensors would fail at the same time is extremely low.

As others have written, I expect the problem is a vacuum leak in the intake system, affecting both banks.

A smoke test using a cigar, a rubber glove, and a length of tubing to connect to the intake manifold is inexpensive and easy to do. And it can be fun!

I recommend you do more diagnosis before leaving to replace the O2 sensors.

Diagnose, diagnose, diagnose is the mantra. Especially before you start throwing parts and $$$ at a problem.

 

I feel its a possibility that they could have both failed as both codes popped up a year ago and was daily driving up until registration expired about 3 months ago. I'll report back with the smoke test results when I can.

 

A cracked intake hose (rubber tube) could cause this reading to be low if the crack is downstream from the airflow sensor. Best to buy new, but can be patched temporarily with silicon.

 

I was looking around the vacuum lines on the passenger side of the truck and I noticed that the break servo vacuum line (the hose with the red clip) was easy to pull it out and was a bit loose. I’ll look around the maf sensor again. Also one of the clips that holds in the the MAF assembly snapped off, it’s right before the sensor but could that be part of the issue?

 

Those clips (or their latch points) always break. Since it's ahead of the MAF it shouldn't cause any problem other than possibly a tiny amount of unfiltered air being sucked in.

 

I think you found your problem, if that hose does not fit snug that could be the cause of the codes. You can seal it with silicone rtv, not exactly oem design but gets the job done. The OEM design is designed to be a quick release. It can be replaced, you have to remove the intake hose, open the throttle, and tap it out from the inside with a long tool.

 

Awesome, I will seal it up tomorrow. I will add some techron Additive and fill up with premium and drive around. Should I Clear the P1171 and P1174 codes, No CEL but they are pending.

 

Yes, clear the codes. Personally I don’t worry about pending codes. If it runs in closed loop and doesn’t throw a CEL I figure it’s not worth my time.