Full disclosure: @Wes Harden is like 99.999% responsible for getting my truck running right.
That's a funny coincidence, @Wes Harden has been a tremendous help on my build thread as well...
Full disclosure: @Wes Harden is like 99.999% responsible for getting my truck running right.
I think code 43 is for ESC, the knock sensor, and the ESC sensor wire goes through the macaroni tube.
2 years ago my k5 was throwing code 43s until I replaced the ESC sensor, it's 1 wire connector, the ESC module and it's connector.
I'm not sure if an ESC issue (code 43) can cause an EST issue (code 42).