Hi, I have a 91 Camaro Z28 with heavy rust problems on the passenger side firewall where the water drains at the inner fender. It corroded so bad it created a hole in the firewall. I am planning on taking everything out of the car to make sure everything is accessible like the and wiring harnes. What steps are involved in replacing an entire firewall?

 

I am not an expert but I believe part of the subframe is there. My suggestion is not to replace the whole thing but to cut out what is bad and weld in a patch panel. You will have to fabricate the panel but it shouldnt be that hard. The key is getting all of the rust and then sealing it with por 15 to keep it from rusting again. You just need a good mig welder.