Error codes 32 and 43?

[1500z71]

Hey guys, been awhile since I’ve posted but I still creep around every now and then.

1993 Silverado 5.7 350 with about 180K on the original motor. Truck has had the service engine light on for awhile now and I finally found the mind to look into it. I jumped A and B and got codes 32 and 43.

I understand 32 has something to do with emissions, but if I’ve been told correctly this will have no effect on performance so that one may not be priority. I’ve tried reading and researching 43, the knock sensor error, but haven’t been able to find a clear path to try to start trouble shooting. This is the one that is concerning to me, but it is worth noting that me and my dad haven’t noticed any loss or fluctuation of power in the time since this light has been on, that’s why it’s been ignored. Truck runs, pulls, idles, starts perfectly it seems. So really just looking for a basic explanation of how I might looking into fixing this and clearing these codes.

Everything is mint on this truck inside and out, AC is icy, bay is clean, but those damned little orange letters on the dash are driving me insane at this point. Thanks guys.

 

[PlayingWithTBI]

Take a look at this thread - we were discussing the same error codes. @randomguy posted the troubleshooting flow chart for your ESC code.

https://www.gmt400.com/threads/o2-sensor-question.45403/page-2#post-1054280

 

[1500z71]

Take a look at this thread - we were discussing the same error codes. @randomguy posted the troubleshooting flow chart for your ESC code.

https://www.gmt400.com/threads/o2-sensor-question.45403/page-2#post-1054280

Thanks man I do appreciate it

 

[someotherguy]

Troubleshoot from low # up. Code 32 is EGR which can sometimes be tricky to fix but is *usually* a bad EGR valve. OEM replacement here only as the aftermarket usually do not work well. Bad egr will contribute to spark knock which does indeed impact performance as the pcm pulls back timing to prevent it.

Code 43 be sure knock sensor is connected and not damaged. It's low on passenger side of block forward of the starter. Common for the connector to be brittle and broken/loose.

Richard

 

[1500z71]

Troubleshoot from low # up. Code 32 is EGR which can sometimes be tricky to fix but is *usually* a bad EGR valve. OEM replacement here only as the aftermarket usually do not work well. Bad egr will contribute to spark knock which does indeed impact performance as the pcm pulls back timing to prevent it.

Code 43 be sure knock sensor is connected and not damaged. It's low on passenger side of block forward of the starter. Common for the connector to be brittle and broken/loose.

Richard

Great information, perfect to get me started. Thank you!

 

[1500z71]

Finally getting around to fixing these issues now that I have some free time before fall semester. Decide I’ll just replace the whole EGR valve, simple and easy hopefully. The knock sensor, unbelievably, was not even plugged in. The male connect looks like someone stepped on it and the copper wire is exposed at the splice. No earthly clue how that happened, but surely a simple fix.

I know this is an old post but I still like to post solutions to this kind of stuff for anyone who ever comes across it in the future having the same issue. Will update this week.

 

[1500z71]

Knock sensor error code and wire fixed after splice a new connector into the existing line. Awesome $12 fix. Installed a new EGR valve as well, and fixed that error code. However, it has been popping back up on long trips whenever I use cruise control or am just driving over 50-60mph. That thing was so caked with carbon though, I may just need to go back in and clean it out.