I've made this post after searching and reading many others here, and elsewhere.
I've got a 350 TBI. All stock. Code 43 from the check engine light as per the mechanic has told me.
The van runs and idles fine.
I don't have the van back from him yet, but I should this coming week. He has sort of tasked me with diagnosing this so we just don't end up throwing parts at it.
I plan to bridge the connectors and read it again. It'll be good to know how to do that.
I've searched around the internet quite a good bit, and I find different suggestions and solutions in each place I look.
The CEL comes on when the van is started. The "BRAKE" light is also on, mechanic found the valve to it is closed, meaning there was a leak at some point. A friend and I plan to replace the whole drum system.
I need to figure out what is causing the CEL without spending money on parts I don't need. I'm decently smart, and I have a multimeter. Everything I've read about this is for engines that are running poorly. The steps and suggestions are written horribly, the posts written long ago, scattered around different off-roading and chevy websites.
I'd really like to tackle this problem when I get the van back. I've got long tube hedmans and the full exhaust system ready to go on, and I plan to have an 02 bung put in. I obviously want to solve this CEL before having the exhaust done, as well as so the CEL is actually a working warning light, and not always on.
I'm doubtful that there is any single source of truth for troubleshooting the code 43, but I would really like to formulate a concrete attack plan. I appreciate the help ya'll.
Last edited by DrCaldre; August 08th 2020 6:40 pm.