Knock sensor

Thank you for that. Now I just went outside and got the engine up to operator temperature and the book states to disconnect the MAF and probe the middle wire of the wire harness and test it for a good ground which I did by hooking up my probe light to the positive side of the battery and probing the middle wire, A, B, C, which is A for PCM, B ground, C Plus, and the light lite up showing ground to the bulb. Now the book says to probe the B and C and it should not show any resistance, and that if it did, 20 ohms would send a code. I get 15 ohms. And I checked my A and B for PCM-V and got 5.5 and the book said no more then 6 and no less then 4, so I guess I am good there but what about the 20 ohms from B and C? Can I buy a new plug for the MAF? And should I get a ohms reading if I check the MAF by probing the middle and right connector?

I did and it was 5.5 volts with key on and no start. This is a 3 wire plug. So if I back take a reading while it is connected to the MAF while running, what should I get?

Alright I will, but I just had it running and back probed the B and C on a DC-20 and it gave me 0.7 and as I increased slightly the numbers did so as well. But I will go and hook the scan tool up also.

Well, now it is not reading anything! I hooked up the volt meter on DC20 and it shows.07 and will increase with rpm's but the scan tool will not show anything.

Yes I did that already and nothing.

I can back probe the plug and all three wires show volts. A-pcm to ground B =6 and B to C shows 7 so the plug works. I have to assume that the scanner is not picking up MAF because the MAF went out somehow or am I wrong?

No, never had. All the book says is to check pin b and c for ignition voltage and if that is the 12 volts you were talking about, then it only shows 2 volts. Now the PCM on wire A and ground shows the 5 volts it is suppose to show but the other showed 2 volts and that was from the start of all of this.

Well I found out that I blew a 10a fuse and I am hoping that was the reason the scanner cannot pick up the MAF. Is there any way to test the MAF by itself?

Should the engine shut off at idle if I pull the sensor?

The reason I asked was because of YouTube I saw where he unplugged it and it stop running. However, I got a first hand experience awhile ago on the matter. I went to get some fuses because I was out of 10a's and I felt something not right while running but nothing really bad, just a bit of a kick around kind of something, then my tac went out all at once, nothing else just that. Then I got home I put in the new fuse and tac worked and now it is reading.7 on the MAF and it increase nice and slow on upping the gas and decreases on down. So if this is working alright, I guess tomorrow I will check the fuel pressure and see if it is alright. Thank you so much for all the help! At sixty six years old, sometimes it can get to be a job.