KrazyK

OK, You asked so I will post this. If you start to hear the tell-tale screech and sqeal when your SAI comes on you can probably save it. It involves disassembly down to the motor and sealed bearings on each end but it is an easy repair.

Mine recently sqealed a few times on startup so I went ahead and did the repair. My SAI is now quite and works fine (no codes).

I will post the DIY with pics if anyone is even remotely interested. If you think Im full of it (as some here do), go ahead and pay the $1500 because I dont give a rats ***.

Hurdigurdiman

Hell I don't know exactly what SAI means K but please post photos of the repair in case mine starts squealing lol. Honestly....

silotwo

Secondary Air Injector. Krazy has been posting some good info with pics on Renntech as well. Not sure why the attitude has to continue - but if one can see past that the info is often helpful - if for nothing more than becoming more educated.

Ubermensch

I wouldn't have asked if I wasn't interested. I solved my problem by replacing the unit with a used one, but I've been planning on taking the original one apart and rebuilding it eventually. My plan was to replace the bearings but I'd be interested to hear what you did. I tried to get a little lightweight oil into the bearings and it quieted it down short term but the noise eventually came back.

Shawn

philooo

What I would like to know is how to remove the SAI altogether... We don't have emission controls down here in Florida and this box is slowing me down

Seriously, any DIY on how to remove all the emission hardware would be great. I mean doing it right without CEL light coming up.

Ubermensch

Philooo, that would be ideal. Unfortunately I've always heard that it requires modifying the ECU programming to avoid the light. I'd love to be wrong, so please speak up if someone knows how to handle this!

philooo

may be some people in charge of the durametric thingy could chime in about cancelling a CEL light for the long term... that would be nice to have. Something like 'always ignore' a particular code.

I also wonder if removing the pump and its hoses would certainly require modifications so that the vaccum system is still functioning with the rest of the engine... If there is actually any need for that system...

I bet the 996 spec racer people have done it.. I'd love to hear about it as well.

Macster

While FL may not have emissions laws I believe you all still have to breathe air down there.

Having said that, I believe that it should be ok to remove the emissions hardware from your street car's engine provided we can have your address so those that want to can dump their garbage in your yard.

The DME is tasked with (among other things) feeding the engine an air/fuel mixture that results in exhaust gases that are most efficiently/thoroughly processed by the converters. These work in a very narrow band of exhaust gas composition.

Feed back is used by the DME to know it is doing its job.

If you remove the converters not only will the CEL come on but before this the DME will seek to arrive at a fuel/air mixture that has the expected voltage signals coming from the O2 sensors after the converters.

Even if you can somehow manage to prevent the CEL from coming on, the very real possibility is the engine will run worse than it did with the emissions hardware present and properly functioning.

To remove the chance the CEL comes on is one thing. To re-task the DME to provide the proper air/fuel mixture without the benefit of the feedback it requires is something else again.

And just in case you are serious about the emissions hardware slowing you down, I seriously doubt that. What is probably slowing you down is your driving ability.

Under hard acceleration -- high torque demand signaled by the e-Gas -- the DME suspends emissions monitoring and enriches the air/fuel mixture to a ratio that is optimum for power (torque) generation. Essentially except for the small weight penalty by its presence, the emissions hardware offers no impediment to performance.

When emissions monitoring is in effect the engine is properly fueled, and thus runs better, more efficiently, cleaner, and thus will run far longer far better than it would sans the emissions hardware.

KrazyK

It might be because it is another thread completely derailed. My intent was not to remove or defeat the SAI. It is considered a part of the emission system and it is probably not "legal" to remove for highway use. My intent was to show those who were interested, an easy repair to save $1500.

So, nevermind, yes I agree. Just remove it.

Sneaky Pete

All you need to do K is keep on the topic. If you haven't realized alot of us tend to go from one to another within the same thread. Big deal.....now you are acting like a little kid and taking his ball home. Boo hoo!

KrazyK

Just trying to be more agreeable this year, thats all. No Problem.

Sneaky Pete

I would still like to know how to repair the SAI. Share the knowledge.

philooo

I already replaced my cat converter with aftermarket one and I had to install some spark plug extended to foul the O2 sensor already.

I don't get any CEL, but I did not know that this might influence the DME fuel mixture... interesting.

I want to keep my car from polluting as I think it is serious business as well, but the secondary air pump is only running for what, 20 seconds. So I figured that the effect is really minimum compared to the time I am driving the car. I am surprised that there is no tolerance for a few seconds until the car reach a base temperature, before testing the gas emission. But again I live in florida, may be the SAI run a lot longer in colder climates ?

69gaugeman

The SAI injects air into the EXHAUST to provide complete catalyst combustion. This also only happens in a cold engine. Removing the SAI will give you a gross HP gain of ZERO. The extra weight removal of what? Around 20lbs will not be noticed in the ***-o-meter at all. So.... I would just leave it on and fix the bearings.....or just unplug it and live with the check engine light...or.....

WalterRohrl

It was 41 degrees in my garage this morning and exactly 0 outside (all Fahrenheit). My SAI was on for almost 30 seconds and then after a 5 mile drive it kicked on again as soon as I stopped in my kids school parking lot (3rd full stop of the day, first after temp gauge at "normal".) Then when I left the school and drove home with several stoplights including a stop for gas it did not kick on again. Remind me not to pump gas when it is 0 outside, not a pleasant experience.

Krazy - I would like to see the procedure for rebuilding it as well if you can spare the time to post it. Thank You.

Macster - Not to derail KK's thread more but I think you were correct it is the SAI kicking on again after I drive for a bit and stop (like I mentioned above). It must have something to do with the car hitting normal operating temp and then stopping in the cold weather. If it ever warms up again (summer?) I will keep my eye (well, ear I guess) on it and see if it does it then as well. The whirring noise sounds the same, just the high-pitched sawblade noise is not present, maybe when warmed up from the engine compartment mine is either expanding slightly in size or the oil in the bearings is flowing better, I don't know...