Hmmm, yeah, and the only way to test to see if it is working properly is to first make sure that the vac lines aren't the problem...
One bite at a time, I guess.
My understanding is that the Air Injection and EGR systems are not directly dependent on each other. But they might have a small affect on performance since the Air Injection system adds fresh air into the exhaust manifold when the ABV/ASV sends it that way, and some of that mixed air is then recycled back into the cylinders for recombustion by way of the EGR system.
One thing you could do, tho, is replace the two check valves to make sure that exhaust from the Air Rail or from the skinny exhaust pipe don't find their way back up into the ABV/ASV system. The one on the air rail is easy to get to. The one on the skinny exhaust pipe is best changed with the exhaust downpipe (pipe between exhaust manifold and cat) is completely removed from the vehicle (unless you have superhuman powers, which, living at 7,200 ft. might very well be the case...), so if you have to do the manifold gaskets, that would be a good time to do that check valve, too.
But the EGR system is definitely a source for both vac and exhaust leaks. Apparently, replacing he EGR j-pipe (from EGR cooler to ex manifold) with a brand new, stainless steele one (instead of reusing the old one and just replacing the gasket, studs and nuts since the face of the old j-pipe has a tendency to warp, so no amount of torquing will get the face flush with the manifold) is the way to go there.
One bite at a time, I guess.
My understanding is that the Air Injection and EGR systems are not directly dependent on each other. But they might have a small affect on performance since the Air Injection system adds fresh air into the exhaust manifold when the ABV/ASV sends it that way, and some of that mixed air is then recycled back into the cylinders for recombustion by way of the EGR system.
One thing you could do, tho, is replace the two check valves to make sure that exhaust from the Air Rail or from the skinny exhaust pipe don't find their way back up into the ABV/ASV system. The one on the air rail is easy to get to. The one on the skinny exhaust pipe is best changed with the exhaust downpipe (pipe between exhaust manifold and cat) is completely removed from the vehicle (unless you have superhuman powers, which, living at 7,200 ft. might very well be the case...), so if you have to do the manifold gaskets, that would be a good time to do that check valve, too.
But the EGR system is definitely a source for both vac and exhaust leaks. Apparently, replacing he EGR j-pipe (from EGR cooler to ex manifold) with a brand new, stainless steele one (instead of reusing the old one and just replacing the gasket, studs and nuts since the face of the old j-pipe has a tendency to warp, so no amount of torquing will get the face flush with the manifold) is the way to go there.
