The check engine light came on so I took my 95 Max to Autozone and they put their code reader on the car and came back with two codes. A bad engine coolant temp sensor and a bad knock sensor. I replace the coolant temp sensor but it doesn't appear that I'll be able to get to the knock sensor.

I then purchased an OBDll reader which arrived yesterday. I read the instructions on clearing codes and followed them to the letter. Long story short...the check engine light is still on.

Here's what I've tried so far to clear the check engine light:
1) Read the "how to" section on this site and tried turning the screw on the ECM. Did not work
2) Tried clearing the code thru the new OBDll reader. Did not work
3) Unhooked the negative cable from the battery for an hour. Did not work.

Hoping someone has another option for me. THanks in advance for any help/ideas you can give.

 

First Q: and this is just me talking, but if I was finding a persistent DTC, my initial question would be, "well, what's the malfunction here?" Meaning, you've got the code reader and you've got a persistent/recurring DTC ... what is the persistent DTC, as in 'what's the code that's being thrown?'

Second Q: and again, this is just me talking. Apparently, the AutoZone "automotive systems expert" informed you, based on his analyses, that you have/had a failing ECT and a failing KS. It's my assumption that based on that info, you purchased, from AZ, a new ECT ... correct? That being the case, is the new ECT really any good?

Point being ... before you get upset about why your car keeps telling you something's wrong and assuming you car is broken, ask your car what's what's wrong. I promise, it knows and it WILL tell you.

 

what make and model number of code reader did you buy?

it is likely that one of our members has the same one, and can help you.

I have been able to clear codes by leaving the battery disconnected overnight.

 

I have a 95 Max. Ive changed both temp sensors and am still getting the error code for a bad temp sensor. I have not changed the knock sensor yet because i dont want to remove the intake manifold. Its 8:30pm here and i just removed the neg battety cable. Ill leave it off for the night and hooefully that will reset the check engine light.

 

You do not need to remove the intake manifold to replace the knock sensor. Of course, you'll cut your hands from the sharp edges inside, but removing the intake isn't necessary.

 

Don't mess with the knock sensor - yet. On these cars, whenever some problem happens, the knock sensor code is tossed in for grins and giggles.

You have a problem other than the knock sensor because the knock sensor DOES NOT cause the check engine light to come on even if it were to be bad.

Find the real problem and fix it. The knock sensor code will most likely be gone too.

 

Lots of good advice in here.

Rather than replace parts, test them first. That's what the FSM is for; it tells you how to test/diagnose the ECTS.

As stated, if and when you get to changing the KS, no need to remove the manifold since you have a 95.