Hey folks, I'm in the midst of removing the upper plenum so that I can get at the rocker covers and replace gaskets. Tightening the bolts did not solve my leak.

Upon disconnecting everything from the plenum, it's evident I have to do something with the SAI "valves". It appears disconnecting them from the cylinder head would be the route to take, as I'm not sure there's a way to get it off the manifold studs any other way.

What do you guys find best to turn those large nuts at the "union"? I tried a large crescent which works fine for the ones with easy access, but the ones in the back look like a real challenge.

Once I got one of the front ones loosened, I noticed the stove pipe is turning with the nut, it must be seized on there. Should I simply use PB Blaster and try rocking the nut back and forth, or is there an easier way?

Any input from those that have done this before would be much appreciated!

 

Well I've doused the thing with PB Blaster and the pipe spins with the nut. In order to get it off, the pipe is going to spin and break.

With that said, can I run the car without SAI? I understand I will have to crimp the lines coming out of the cylinder head and weld them closed. I'd like to get rid of that stupid system anyways, but I want to make sure there will be no permanent SES light because of it. I would leave the control valves hooked up but they wont go to the cylinder head obviously...

I know of no other way to break these nuts loose. Poor design IMO.

 

Use heat. Get a propane torch and direct the heat on the nut. It will help to break the bond between the nut and the pipe.

 

Flare nut socket is your best bet.


You need to get a wrench to hold the square part of the union pipe fitting while you turn the nut.


It can be a pain in the A$$ to get that sucker out for the first time, but take your time and be careful because those things are not cheap to replace.

 

Well I was too impatient and twisted the stove pipe all to hell, so this is a one way road I'm going down now, that only leads to removal of the SAI garbage. I want that stuff out of there anyways, that engine bay is way too crowded and the SAI stuff couldn't be in a worse place when you have to do maintenance like plugs and wires.

That said, what is the trick in keeping the ECU happy so as not to throw a code(s)? Obviously a non-SAI ECU would do the trick, but I don't want to spend the money if I can avoid it. The SES light is more of an annoyance than anything (dash lights / warnings bug me), as there is no emissions testing done where I live. You can drive anything that you can get to roll down the road here.

Looking at the system, it seems pretty "dumb" as in there are only two wires going to the pump for the electrical load. I suppose the ECU could sense a draw on that circuit to determine if the pump is running, but an electrical load is easy to recreate if that's what it takes.

There are no sensors on the valves themselves, so the only other means the ECU has to monitor the SAI performance is the O2 sensors, looking for a high or low (I forget which) voltage which quantifies the additional O2 being added into the exhaust.

While not impossible, this would require a little more work than I hope to have to put into this, but a small PCB with a couple relays and voltage regulator spliced into the O2 wires would give the appropriate signal at startup, then hand off to the actual O2 sensors after a predetermined amount of time.

Anyone try this and or know what codes it will spit out?

What determined whether a vehicle got SAI or not? Were all petrol engines intended for the North American market equipped with SAI? Or was this a state by state thing? I know my vehicle does not have CA emissions, it was originally sold in Rhode Island or Massachusetts (forgot which).

 

On a side note, the plenum is FINALLY off. I resorted to taking a cut-off wheel to the stainless risers that attach the SAI valves to the stove-pipe. Obviously ease of maintenance was not a primary consideration in the design / layout of the engine bay and assorted components.

 

Switching to non SAI may be as simple as removing the components, plugging the SAI ports in the heads and having the dealer or somewhere with a computer plug in and switch or turn off the SAI. They are able to do the same thing with the air ride suspension so I assume the SAI is similar.

 

SAI is hardwired into the ECU from what I've read. You either have it or you don't, no way to program it out.

Ripping the components out is the easy part, getting the SES light to go away, not so much... But I'm open to suggestions from anyone's whose been in this spot before.

 

sorry, this is out of my league