Knock Sensor Failure

[picks]

Sled is giving ecu 21 code (knock sensor failure). Air/fuel numbers are good, should be rich enough 11.5-11.8 WOT and should be plenty of octane in fuel for amount of boost (about 9lbs). Has not given ecu 23 code. Have been adding fuel to richen because scared to burn down but sleds then sounds and acts rich. Anyone else have problems with bad sensors? Or is it truely a lean condition? Any ideas? Thanks

 

[spooled flatlander]

Do you have a fuel pressure gauge? iirc 21 is mild det and 22 is hard det. I would start with a gauge, make sure you are getting enough fuel first

 

[picks]

yep, I have guage and fuel pressure is right.

 

[jensen]

Sensor

Make sure your sensor is screwed down tight to your head. If it's loose and it will throw that code until you tighten it.

 

[picks]

Checked sensor and it is tight in head, also did a search for info on here but couldn't find much. Anyone else seen this code come up?

 

[XP Rob]

What does code ecu 23 indicate.

 

[picks]

ecu 23 code is: knock control fail safe mode activated.
I am wondering why this code isn't coming up if it is a lean condition.

 

[picks]

ttt
Anyone getting ecu 21 code?

 

[m8matt]

had the same thing happen to me last year.....your sensor is probably shot. Change it it out with one of your buddies sled to verify.

 

[harf69]

i heard alot of people had the knock sensors being triggered i guess they are really sensitive