LT1 Stumbles with Code 43
Thread Starter
Racer
Joined: Dec 2002
Posts: 289
Likes: 0
From: The wrong side of the Atlantic ocean
LT1 Stumbles with Code 43
Hi all 
I was driving without any problem when I saw the "Service Engine Soon" coming on...
After that the car stumbled at around 70 MPH (1800 RPM) when I was giving a bit off gas but not If I kicked it more...The light stayed on till I shut down the engine.
I then pulled the code out and it was a 43 (knock sensor)
My car is a 92 LT1 with 70700 Miles.
What can be the problem ?...and above all : How can I fix it?
Thanks for your replies and have a good one.
I was driving without any problem when I saw the "Service Engine Soon" coming on...
After that the car stumbled at around 70 MPH (1800 RPM) when I was giving a bit off gas but not If I kicked it more...The light stayed on till I shut down the engine.
I then pulled the code out and it was a 43 (knock sensor)
My car is a 92 LT1 with 70700 Miles.
What can be the problem ?...and above all : How can I fix it?
Thanks for your replies and have a good one.
Le Mans Master
Joined: Jan 2000
Posts: 6,595
Likes: 1
From: Thornton CO
Probably just replace the knock sensor(s) and you'll be good to go. It is a messy job though - as soon as you pull them all of the coolant comes out of the block with them! It's a great time to do that coolant flush that you've been putting off 
Le Mans Master
Joined: Jan 2000
Posts: 6,595
Likes: 1
From: Thornton CO
I can't remember exactly how much it cost but you can go look up the parts on http://gmpartsdirect.com and get an idea. Maybe less than $100 a couple hours of gettin dirty. I give it a 2 on a scale of 10 for degree of difficulty.
Melting Slicks
Joined: Sep 2003
Posts: 2,270
Likes: 118
From: N. Babylon NY
Hi,
I had a problem with this circuit also. I checked the circuit 3 times-always checked out o.k. The 4th time I found a bad knock sensor. If I had to do it again I would still check the circuit. But this time if it all checked out o.k. I would go ahead a change the knock sensors anyway. I would recommend a 5 gal pail as it is taller and will catch all fluid. Also don't overtorque the sensors (14ftlbs).
Easy job!
Steven
I had a problem with this circuit also. I checked the circuit 3 times-always checked out o.k. The 4th time I found a bad knock sensor. If I had to do it again I would still check the circuit. But this time if it all checked out o.k. I would go ahead a change the knock sensors anyway. I would recommend a 5 gal pail as it is taller and will catch all fluid. Also don't overtorque the sensors (14ftlbs).
Easy job!
Steven
...I have to wait till this job is done first.
Team Owner
Joined: Oct 2000
Posts: 96,443
Likes: 9
From: Fort Knox, KY
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Even BEFORE you replace it, inspect the wires that lead to the sensors (LT1's have one on each side.) If they're caked with oil, grease or grime, spray 'em with some WD-40 then re-install.
I had a leaking intake that allowed oil to run down and get on mine and interfere with the electrical signal. After I replaced the intake gasket, I cleaned the sensors, cleared the ECM codes and it's been fine ever since! ALWAYS assume the simple when it comes to car repairs.
I had a leaking intake that allowed oil to run down and get on mine and interfere with the electrical signal. After I replaced the intake gasket, I cleaned the sensors, cleared the ECM codes and it's been fine ever since! ALWAYS assume the simple when it comes to car repairs.
