Can OEM exhaust manifold crack be repaired?
The engine on my '92 SSE */c was rebuilt shortly before I bought it, and the receipt noted that the exahust manifold was cracked. I looked at the front manifold at that time and didn't see a crack so I didn't think I needed to worry about it...until now (see my other post about SES and error code 44). The car has had a rough idle since I've owned it, but hasn't had any other longstanding driveability problems.
I replaced the rear valve cover gasket a few days ago, along with the plugs and wires, and I saw a small gap, maybe 1/16") in part of the welded joint near the o2 sensor, and now that I'm getting an SES error code 44 (o2 sensor lean) I wonder if maybe the crack is getting worse and needs to be repaired. The crack is upstream, a few inches before the o2 sensor joint. By the way, the plugs looked good after 40,000 miles, hardly worn electrodes, all same grayish color.
Can the OEM exhaust pipe be welded at a muffler shop? Or is there a high temp epoxy or something I can use to fill the crack?
'99 Bonneville SLE, white, 112,000 miles
'02 Park Avenue Ultra, white diamond pearl, 88,000 miles