I've tried to my research on this, but with minimal luck...

I'm replacing the passenger side exhaust manifold and I noticed the air injection lines have a leak at the collector (the area where the tubes come down for each exhaust port). I also noticed that the hose that connects the cat pipes had deteriorated and has a hole in it.

I really don't need to get rid of the air injection system/emissions, I just want to know if it is going to hurt anything if there is a leak in the system and what the effects will be. Do I need to fix it or can I leave it?

 

The smog pump is only there to pump in air (oxygen) into the cat so the cat can burn as much unburnt fuel as possible. No, it won't hurt your motor with the tubes to not be connected. What that might mean is you have a few more emissions coming out the back than if it were all working correctly. There are no sensors on the smog pump so there will not be any codes captures by the computer.

 

Good to hear. I don't have emissions in my area, so it isn't a big deal if it doesn't meet. I just wanted to make sure it wouldn't cause any issues with the EGR or O2 sensor that would give me worse milage.

 

No sorry Rikil that is completely wrong. There cannot be any leaks in the exhaust system or anything attached to the exhaust system upstream of the O2 sensor or the EFI system will not be able to control fuel mixture and the motor will run excessively rich or lean.

 

The tubes are downstream of the O2 sensors, are they not?

 

No the tubes inject directly into the exhaust manifold (4 per side) and from there into the cat I guess. It's all up stream from the cat.

 

OK, I was thinking of where they go to the cat. Conanski is right in that I am wrong.

 

You have the oddball version of this system that was not very common, most engines just have a tube across the back of the motor attached to ports at the back of the heads or to the back side of the exhaust manifolds for HD trucks. It's anybody's guess why Ford felt the need to invent 3 or 4 different versions of the same system but that's life with these trucks, there are more exceptions to the rules than rules.

But in any case you need to put all new parts on this motor or remove it all and plug all the holes where it attached to the exhaust. It might be easier to just put a different set of manifolds on it or even shorty headers.

 

^^^^yup. I'm already in the process. I'm pulling it all out. I just need some help on what I can take out and what I can just cap off. I'd like to take everything but the pump if at all possible. I'll probably leave my EGR tube also. As for the manifolds I'm going to cut the lines and roll the ends. I can't get them out of the manifold and new manifolds aren't cheap.

 

Ok, so I've read up on this and I don think I have the system with the holes in the head, I have holes in my manifolds. Those are easy to plug. My big question is it looks like the TAB and TAD solenoids have their own vacuum lines. What do I do with those vacuum lines after I remove the hoses and pies, etc? Can I remove all the valves as well?

 

TAB and TAD solenoids need to remain electrically connected but you can completely remove the vacuum lines between them and the associated valves.. or just cap them off. When I did this I remove the whole vacuum harness from the motor and deleted all the extra lines.. but you need the upper intake manifold off to do that.

All plumbing in the system behind the pump can be removed, I reused a small section of rubber hose to reattach the outlet muffler to the pump just to muffle the noise it makes. All points where the tubing attached to the exhaust system must be sealed air tight.

EGR is a separate system and cannot be eliminated without setting codes so I suggest you leave it alone.

 

Not touching the EGR, except to replace the tube and gasket.

Thanks for the info on the air system. That will make my life tons easier! I also plan to take the upper intake manifold off to replace injectors and re-route my spark plug wires, sixlitre tune-up, etc...