Question-------------------------
Followup To
Question -
Help!!!!!! I have a 1993 GMC Sonoma 4.3 with an engine code Z . I guess by now I have spent 900.00 to 1000.00 dollars over a period of 7 years trying to find out why my check engine light keeps coming on giving me the knock sensor code. The sensor was replaced in April of 98 by dealer, I get the code again in March of 99 which I replaced, and again in Jan., 01 I installed another one. The light never went out. I then took it to dealership on Jan 18, 01 to find the problem. They first installed a new knock sensor. I brought the truck home the light still comes on. I returned to the dealership they rewired and rerouted the wire to the knock sensor. I left and it still came on. I returned again on Feb 2, 01 they replaced the EPROM and PCM. The light still came on. I did not return because they said they didn't know what the problem was 600.00 dollars later. I have noticed it comes on first thing after setting for a long period of time and doesn't come on when it's warmed up. I have also gone back in my paper work and noticed I have replaced my converter Jan 13, 01 and again May 22, 04. I have recently had an O2 sensor put in. Here are some other things I have tried over the years. Changed gases, octane boost, I have had regular tune up, including wires, cap, rotor. The truck has 130,000 miles on it and I have taken very good care of it.Can you please please please help me?
Answer -
Obviously guessing has not worked.
FIRST I need to ask some questions.
what size engine ?. 4.3liter V6 Z engine code
What code number is the computer storing for the knock sensor ?. Code 43
You stated that the CONVERTER was replaced. catalytic converter for the exhaust system or the torque converter for the transmission ?. Catalytic converter for the exhaust
autohelp
AnswerThere are numerous things that can set a code 43 such as:
1. faulty knock sensor. I have even seen BRAND new ones right out of the box that were faulty and some that lasted days, weeks and some for only months or years. The knock sensor resistance needs to be checked as well as the ECM voltage to the knock sensor as well as the knock sensors ability to detect detonation.
2. Incorrect ignition timing can cause a code 43.
3. knock sensor wires to close to other electrical wires causing interference.
4. faulty MEM-CAL.
5. Faulty ECM.
6. Loose torque converter bolts can set off the code.
7. Carbo buildup on the top of the pistons can cause a detonation and set off the code.
8. A slight engine bearing knocking noise can also set the code.
9. Just about any noise from anywhere that is loud enough for the knock sensor to detect will set off the code.
All of these things need to be checked.
autohelp
