Drifter36

I’ve been working mostly on the interior and am just now beginning to check out the engine etc
This car sat in a warehouse for close to 20 years and was not running.
After a new fuel pump and filter I was able to get it running by installing a new CTS, MAP, EGR. TPS is spot on. I’ve also replaced the usual wires, plugs, filters etc. It has an oil leak from what looks like the valve cover gasket so I’ll be doing a tear down of the intake manifold fairly soon. Right now, I have no codes showing.

So here is my question. I started ripping out the exhaust system today and found the passenger side Y pipe coated with a layer of soot and the driver side virtually clean. See photos below.

Any thoughts on what might be causing this? I have not yet changed the oil or coolant but I don’t see any contaminants on the dip stick.g

I’ve been using the collective wisdom from this forum and I’ll be checking back with more information as I get into the engine a bit more. It’s a high mileage motor. 180k. I’ve only put a few miles on it since I took ownership but have not noticed a change in coolant level.

Thanks
Bob