Secondary Air Injection removal

Originally Posted by 330i ZHP

why wouldnt you just leave it - it doesnt sap power and only runs at cold startup

Here's what happened

I originally took mine out because it saves 7 lbs off the front of the car and looks a lot cleaner in the engine bay with it out. I left it in my basement thinking I could just re-install it once inspection time comes around, but my basement got flooded during a storm and pretty much destroyed it....so now I'd rather get a simulator than spend all that money on a new one.

Originally Posted by secono330ci

Here's what happened

I originally took mine out because it saves 7 lbs off the front of the car and looks a lot cleaner in the engine bay with it out. I left it in my basement thinking I could just re-install it once inspection time comes around, but my basement got flooded during a storm and pretty much destroyed it....so now I'd rather get a simulator than spend all that money on a new one.

Took mine out with the windshield washing reservoir as well and really cleans up the area.. Super easy to check for vcg leaks too

that sucks

Originally Posted by rkneeshaw

Evolve's website doesnt show the pre-2005 330i as an option? They seem to only tune for the n52 and newer cars, or the e46 m3.

Contact them. They will do it but unless you really have a special car or special needs it isn't worth it. They even told me that. But the more built your car is and the higher your desire to stay legal becomes, the more they look like the only option!

contact eurocharged, as well. they tune all sorts of e46's

Originally Posted by F1004fun

There is a way to make this work with MS45, you would need an additional relay that could jump that little mini MAF on your SAP from the 5v wire that supplies it to the signal wire out of it with a resistor that would give you about 3v or so. This would make the pump looks like it is moving air and should set the monitor. If you were interested I could make a wiring diagram and you could do most all the work just through the e-box lid.

So this is interesting, all the newer SAP have a MAF on them. In particular, any m54 with the ms45.1 DME have it. Apparently its an easy way to tell you have a ms45.1 DME.

Originally Posted by TxZHP04

Secondary air operation described starting around p37:

http://www.bmwmotorsports.org/BMW_docs/m54x5.pdf

The context is X5 but the motor is still M54.

And this is a GREAT document, but its for the ms43 DME.

So now I wonder, why would BMW add a MAF to the SAP if it wasn't to monitor whether it was working or not? And if that was the case, does that mean the DME isn't checking the O2 sensors as a way of monitoring the SAP? And then finally, does that mean that in the ms45.1 cars removing the SAP is as easy as making a SAP MAF sim, and there's no need to touch the O2 sensors at all?

If only I could find a document like the one TxZHP04 posted but for the ms45.1....

I do have a question about the SAP Procedures...

I know that during cold start up. It will come on and my AFR will hit 22 for a few seconds and then turn off.

Then I see my Timing goes all over the places for a good 10-15 sec and then go away.

Do any of you guys experience this?

-Trip

well I think thats what we're trying to figure out; if we can disable that SAP system just by using a SAP MAF sim. It doesnt appear that the SAP sims designed for the MS43 DME's would work because they dont address the MAF on the SAP found in our MS45.1 cars

Originally Posted by rkneeshaw

well I think thats what we're trying to figure out; if we can disable that SAP system just by using a SAP MAF sim. It doesnt appear that the SAP sims designed for the MS43 DME's would work because they dont address the MAF on the SAP found in our MS45.1 cars

I'm thinking I might have to find a Tuner to Turn it off if possible...

Maybe thats an option. I did ask ESS a while back and they said they could not turn off the SAP monitoring, but someone else said evolve or eurocharged might be able to do it. Being that your boosted might complicate things further. Maybe ask AA if they can turn off the SAP monitoring or tune around it somehow?

Originally Posted by rkneeshaw

... does that mean that in the ms45.1 cars removing the SAP is as easy as making a SAP MAF sim, and there's no need to touch the O2 sensors at all?

In an email gpeterson mentioned a good way to test this: on a MS45.1 car we could unhook the output hose of the SAP that connects to the head and go through a couple cold starts and see if a SES code is thown. If the car throws a code then we know its monitoring the O2's AND the SAP MAF, but if not, then the MS45.1 DME must only monitor the SAP's MAF.....

My car is in the garage of the winter so I'm going to wait for good weather to test this..... unless anyone else in the southern states wants to give this a shot?

I would do it but mine is boosted. So wont work...

For you guys with MS45.1 that want to remove the SAP, we can use the same concept that we did with the MS43 with one additional circuit. So for they MS43 we used two resistors (75ohm I believe) to pull the pre-cat O2 sensor signal to ground through a DPDT relay and make the voltage go down to .200V.
So if you look at the small MAF you have three wires, 5v+, ground and a signal wire. If you measure between the signal wire and ground at rest and upon SAP activation you might find about .025V at rest and about 3.50V at normal pump flow. If you take a DPST relay and use is to switch between two resistors that come from the 5V+ wire and have a value that gives you a voltage drop down to the level you need. Once you find the right values your DME will see the rest voltage because it is always checking the MAF circuit for disconnection. And when triggered you will have the voltage needed to simulate flow.
With the MS45.1 it's way more work to go through for the 7lbs. and the cleaner engine bay, but honestly I would be doing it too. Maybe just for the challenge.
For the ultimate challenge the SULEV cars with their wide-band pre-cat O2 sensors would be a real tough one to fake.

F1004fun, do you know for a fact that the MS45.1 DME is checking pre-cat O2's AND the SAP MAF for proper SAP function? I'm entertaining a theory that the O2's might not be monitored for proper SAP function with a MS45.1 DME because it seems that would be redundant as it is being done by monitoring the SAP MAF....

I installed M54 engine in E36 chassis and I do not run any of the emissions stuff. I am using MS42 and MS43. But for MS45 I did not get that far into it.

It can all be deleted from the program and it won't trow check engine light, emissions rediness will always stay 'not ready' for the deleted components.

Originally Posted by rkneeshaw

F1004fun, do you know for a fact that the MS45.1 DME is checking pre-cat O2's AND the SAP MAF for proper SAP function? I'm entertaining a theory that the O2's might not be monitored for proper SAP function with a MS45.1 DME because it seems that would be redundant as it is being done by monitoring the SAP MAF....

I would say yes, MS45.1 monitors both. The reason I say this is I remember a car with secondary air faults that turned out to be a torn hose from the pump to the valve. I was seeing flow through the pump but not enough change in the O2 voltage. And I know for a fact that the SULEV cars look at the time delay between pump activation and pre-cat O2 signal to determine how effective the system is. Those are a pain in the a$$ to diagnose.

well that sucks.