Expert: Van - 1/5/2006

Question
Hi there:

How can I get the check engine light to go off in a 1994 Chevy 1ton 454 when I replace the knock sensor?

Also, what would make a 91 chevy 2x2 350 stutter at between 32 and 35 mph when at a constant rpm?

Thanks a bunch for your time,  Toni

Answer
Hello Toni,
The light, I would first try disconnecting the battery for a few minutes.
If that doesn't do it, and you are sure it needs a knock sensor, replace it and drive a while. After several operating cycles, some codes will erase themselves if the problem has been corrected.
If neither of those turn it off, you may need to have a scan tool connected that can erase codes.

But, are you sure it needs a knock sensor, or are you just getting a code that says knock sensor?
The knock sensor could be trying to do its job, but there is just too much for it to compensate for.
You could just have a vacuum leak, like maybe the EGR valve sticking open.


The other truck.....I would check the fuel pressure for one thing.
I'm sure there are several things that would make it do that.
The throttle position sensor could have a bad spot.

Van

Van