Jbrew

Nope, the Y, manifolds, O2 bungs can't leak a whole lot. If you have bad leaks you'll get those 420/430 DTC's and it won't pass emissions. Do a good job and you won't have any problems. Your still OX compliant,- unless you live in California.

2thousand5.4

I cant weld nor do I have access to a welder so I will be having the big al's or some other shop weld in the cats or pipes. When I put on my magnapack I just clamped it. And I live in VA and we know the guy who does the inspections so hes a little easy on us

Jbrew

Cut those two off in the back first, keep them. I got $160 for all 4 on the 98, - some guys were getting near $200. So the two big ones are worth around 100 bucks at a scrap yard.

Then drive the truck to Big Al's with the Y open and tell them what you need.

Bring the truck back home after it's done, disconnect the battery for about a half hour or so to clear the KAM. Reconnect (posi first if you removed both cables).

A leaky muffler doesn't matter, just from the Y forward.