I read in Chilton's and Hayne's manuals about the A.I.R. System, and how it's supposed to help during cold operation. One thing they don't mention is the answer to: Can the whole system be removed without screwing up sensors?

Someone before me ripped out the pipe that went to the cat, and sealed it off at the cat, and left it open at the top. The filter element is also gone (was supposed to be right behind the alternator) and that hole is wide open. Is it safe to remove the rest of the system, and cut off the induction from the exhaust manifold? It currently comes up and joins together with check valves. Since so much is missing, I'd like to remove it completely, and cut off and weld together the 4 spots it comes out of the exhaust manifold, but don't wanna screw up all my sensors in the process. So yea or nay, car techies?

 

The system actually operates in two different modes: to the manifolds during cold, open-loop operation; and to the cat during warm, closed-loop operation. The idea is to get more oxygen into the exhaust to help complete the burning process, and to the cat to aid in its job.

When cold, you want the extra oxygen at the warmest point possible, which is right at the exhaust ports. When warm, there's two reasons you don't want it at the manifolds: 1) so it doesn't "fool" the O2 sensor, and 2) because the reactions taking place in the cat makes it the warmest place.

So, you can eliminate the entire system with no effect whatsoever on the sensors. The ECM does send a signal to the diverter valve, but to the best of my knowledge, not having anything to receive the signal will not set any trouble codes.

 

currently it's fooling the o2 sensor, since it is missing a check valve. it keeps giving me a 'lean' signal. (Although I had it checked at a shop, and it's running somewhat rich). I was told that since it's pulling in air without the check valve, that's why it keeps setting a code as it reaches normal temp (trying to change modes and still pulls air in, and o2 sensor sees too much air, not enough exhaust). At your approval of the idea, i'm gonna rip it all out and weld the ports in the manifold closed. Hopefully it ifxes the bad runnning condition a bit. (Again, the shop told me that the computer, seeing a lean exhaust, is overcompensating.. they wanted me to replace everything, but i thought removing it, since i don't have to worry about emissions, would do just as well) thank you, and time for the hacksaw.....

 

I unplugged and ripped everything out, and no problems yet

 

You dont need to have the holes welded shut. If they are cast iron manifolds, those can be plugged with a brass pipe thread fitting, cant remember the size. I think its 1/4".

 

I ripped all my air stuff out. You'd have no idea how much it cleans up the engine bay too! Saves some weight... didn't notice a performance change at all (increase or decrease.) No codes set either. I'd say on a day when you have nothing better to do-go for it .

 

Well, had to go to work, didn't get around to it, but I'll take care of it tommorow. Might be something fun that I can do for free to my car, quite rare.

 

The check valves are just there to protect the diverter valve and pump. Most likely, you've got a diverter valve problem.

Taking it out will certainly "solve" the problem. Better hope you don't get transferred to an emissions-testing area...