Unfortunately yes. You can verify it with a combustion chamber leak down test. If you're not able to do that you could at least check compression. Usual suspect is between 5 and 6. But also can fail other places.
Post #4 I thought that was the one for the firewall. Sorry that I did not mention looking for the one on the engine block. I do also need that one and I order to have that one I will let you guys know if that also works for the block. appreciate your response thanks again.
Yes moving the power steering reservoir you can get to it I believe it's a 24 mm. More than likely you're going to break the connector especially the knock sensor connector. You can check temp sensor values at the computer, fairly easy to pull out the computer. And you probably won't break...
Also if the sensor is out of range and not switching back and forth within a period of time, it will set a code. No need to be replacing everything you can check with a
DVOM or a fast voltmeter like fluke 88 for example.
I agree with O2 sensors degrade, the computer doesn't rely on oxygen sensors to do significant amount of fuel trim. It relies on oxygen sensors to fine-tune fuel trim. Significant fuel trim is provided by air fuel meter and coolant sensor also throttle position sensor.