MAF and knock sensor codes for the 3rd time in 3 years

[95se]

I was driving on the highway yesterday and check engine light came on. I went to autozone and had them scan it. Knock and maf sensor codes came up again. Originally back 3 summers ago a ground wire to the wiring harness was broken. Mechanic repaired it then it started cutting out again and engine light came on so he replaced the maf with a used aftermarket one. It lasted 8 months then same problem occurred. Check engine light and it was cutting out. Replaced it with a used factory one. Has been good for about 2 yrs now then the check engine light came on again yesterday and it slightly cut out once. Knock sensor was replaced back around '08. Any ideas.. This is getting frustrating!!

[anti tyler]

well if your light is saying mass airflow sensor and knock sensor then that's what your issue it. Whether it be the wiring to either, or the sensors themselves. Something is not right. Have you used a volt meter to test the wires resistance? make sure it's not broken somewhere?

[95se]

How do u do test the resistance?

[anti tyler]

Put your multimeter on ohms (upside down horseshoe) and test the mass airflow sensor. (Resistance readings can be found online)

Then I suggest getting long enough probes to test the resistance from the plug all the way to the ecu. To make sure the wire isn't broken anywhere.

[95se]

Aren't there several holes in the connector of the maf. Which ones do u test. Do u have a pic. Also the ecu is way under the dash I assume..

[bad dog]

i replaced 3 knock sensors on a nearly stock 97 , got tired of that and cut the wires and installed a 440,000 ohm resistor across the wires, tape it up nice and clean , now the ecm thinks the ks is ok .

[95se]

Am not sure if it would have anything to do with it but I have had a list of subtle electrical issues starting in '03 after an aftermarket amp was put in.

1) Batteries and starters going out prematurely which an electrical shop diagnosed as the amp draining the battery down too much overnight thus causing the starters to not get the proper voltage. Since then I have unplugged the amp wire from battery and it seems the battery is lasting longer so far.

2) factory alarm going off randomly

3) tach cutting out. Occasionally when I turn the fan on the needle drops to 0.

[PPman]

The MAF is bound to go bad every few years regardless of new or used, a good cleaning of the mesh and sensor usually fixes it. When that is not enough usually the square where the plug is needs to be opened and the contacts from the board to the plug need to be cleaned and soldered together, vibration over time will break them apart and create false contact. I have done that to mine because of the same issues you are having.

The knock sensor you can just unplug it, reset your computer with a scanner and the computer will think nothing is wrong with it, or just replace it (best option just not the easiest).

Better and cheaper to repair the MAF than to just buy a new or used one that will go bad after a while.

[95se]

The MAF is bound to go bad every few years regardless of new or used, a good cleaning of the mesh and sensor usually fixes it. When that is not enough usually the square where the plug is needs to be opened and the contacts from the board to the plug need to be cleaned and soldered together, vibration over time will break them apart and create false contact. I have done that to mine because of the same issues you are having.

The knock sensor you can just unplug it, reset your computer with a scanner and the computer will think nothing is wrong with it, or just replace it (best option just not the easiest).

Better and cheaper to repair the MAF than to just buy a new or used one that will go bad after a while.

My original MAF lasted till 6/2012. I put on the injen intake in yr 2000 but since 2013 I've gone through one and the code has been thrown again I think it maybe in the wiring that's causing them to short out but who knows. Is it normal for a knock sensor code to be thrown with the maf code? Knock sensor has been replaced few years ago.

[PPman]

Don't know for sure if normal, but I have always gotten both, but then again my knock sensor was old as hell and one of the prior owners unplugged it and cut the harness, now thanks to wiring specialties I replaced that and the knock sensor. So far it has been around 2 years since i soldered the connectors and replaced the knock sensor with no issues.