O2 Sensor code - P0053 Heater resistance Bank 1 Sensor 1

[Enjoyneering]

Good day everyone,

New update guys. After I've figured out that the wiring is OK it is a time to look at other options. The ECU always throws two codes: P0053 & P0133.

What causes the P0053 code?
- Faulty HO2 sensor. (Unlikely it's broken, but it's a chance it's not the right one (it's not certified by GM). So I skipped for now.)
- Damaged or disconnected electrical connector at the oxygen sensor (Checked. OK)
- Faulty or shorted wiring in the oxygen sensor circuit (Checked. OK)
- Blown fuse for the HO2S sensor (Checked. OK)
- Low or excessive fuel pressure (Don't have a pressure gauge. So I skipped for now.)
- Vacuum leak on the engine
- Excessive exhaust leaks
- Faulty ECU (Engine Control Unit), in rare cases (Unlikely it's broken. Don't have a oscilloscope. So I skipped for now)

What causes the P0133 code?
- A faulty O2 Sensor (Unlikely it's broken, but it's a chance it's not the right one (it's not certified by GM). So I skipped for now.)
- A leaking exhaust manifold
- An engine vacuum leak
- An open or short in the wiring of the O2 sensor (Checked. OK)
- Soot or oil buildup on the O2 sensor (excessive buildup) (Sensor is new. OK)
- A dirty mass air flow sensor (Cleaned two moths ago with carb cleaner. OK)
- Incorrect fuel pressure

This codes have three things in common:
- Low or excessive fuel pressure
- Vacuum leak on the engine
- Excessive exhaust leaks

I don't have the pressure gauge so skipped the first cause for now. Vacuum and exhaust leaks are easy to check. So i did and guess what - I have a vacuum leak in the third injector. Ordered injector seal kit for 32CAD. Will try this weekend. I'm pretty sure it's going to fix P0133 code and doubt about P0053.

The ECU algorithm for P0053 code is:
- The ignition is switched off for more than 8 hours. (this is why almost everybody has this code after 3 warm ups )
- The difference in temperature of the engine coolant (ECT) and the inlet air temperature (IAT) is between 8 ° C (14 ° F)
- ECT temperature is in the range from -30 to + 45 ° C (-22 to + 113 ° F)
- The ignition voltage is less than 18 V
- The duration of engine operation more than 200 ms.
- After performing the above test conditions, P0053 run once for each engine start from a cold condition.

As you can see all this tests conditions don't have any relation to vacuum, exhaust leaks and low or excessive fuel pressure. But who knows it's GM. We will see this weekend.