SAI Delete

Hi I have been reading about this and cannot see a lot on this. To my mind it seems like a good idea to delete the system. Some well known 911 experts blame the propensity of the M96 engines to score bores on the system (washing fuel off the cylinder walls). Apart from the CEL it is not an MOT issue as such in the UK AFAIK. Can the ECU be fooled into not throwing a CEL if the system is removed? Tks! Berni

What benefit is there removing it?

The secondary air pump dumps air into the exhaust manifold as a means to fast warm up the cats .. I'm unsure how this could possibly cause bore wash issues but am always open to advise . The car monitors this system and should throw up a fault code if this system is not working .. later on it should trigger the eml . I have a Panamera in with eml and this system inop on one bank atm .

My thoughts exactly.

Hello Guys As I understand it the SAI dumps air into the exhaust and causes the car to enrich the fuel and is a mechanism to heat the cats up more quickly. This causes bore wash. Especially if you let the car tick over to warm up. This Jack Raby video talks about the process in detail. Wind forwards to 19mis approx........ https://www.youtube.com/watch?v=-T6VrwRSQ0I Maybe its not a major issue. Put the frighteners on me though. All the best Berni

I have deleted it on a 2001 car. The early cars did not have it, later cars do, I forget the year. - It's an emissions thing. If you have an SAI you will have pre and post cat sensors. When you delete the SAI you only need a post cat sensor. You will need to code it out, to avoid CEL. Benefits for me, no SAI pump, weight saving, albeit small, more space and airflow in the engine bay, two less cat sensors, less to go wrong.

I always thought more fuel was put in due to the exhaust fumes being diluted but was tld on here I was wrong and it was the ecu that was programmed to add more fuel at start up and not governed by the SAI. Unless you modify the ecu it seems pointless removing the pump.

You need to change the coding on the ECU from EOBD to RoW. MC

An interesting hypothesis .. SAI is injecting air direct into the exhaust so the car gives more fuel .. this is indeed how a cat fast warms .. cars since they were first designed have operated this way though before Cats were even invented .. a cold engine and the fuel injected condenses on the cold surfaces so more fuel is injected to compensate for this . This quickly slows and then stops as the engine warms up .. early Porsche cars had a seperate fuel injector for cold start . If the SAI is removed and coded off then does it inject less fuel :?: I don't know , i doubt it , but if it doesn't then removing the SAI is pointless . Porsche designed these cars to work this way .. if i had to trust someone then it would be porsche over some guy on youtube but again i don't know .. perhaps Porsche don't know what they are doing ? Not allowing the car to idle up to temp as its bad for the engine .. hmm .. Hopefully i got this wrong .. every mechanic on every car for every manufacturer runs the car up to operating temp in the workshop on a service .. I don't know how many mechanics there are in the world but rather a lot i feel .. in this case are we all wrong .. again i might have missed something here .. been a long day and i'm tired . Interested in a discussion on this though with those that know more than me .. always open to learn something .

The key thing on certain cars is that there were two versions of the ECU code. A RoW map which was designed to run with 2 lambda sensors and no SAI, and an EOBD map which was designed for SAI and 4 lambda sensors. So when you 'code it out' you aren't telling it to ignore SAI faults, you are running a different standard config which is not expecting to see it. As such, fuelling will be correct for running without SAI. You can block off the fitting in the block, and remove the hardware which is not required. MC

I wouldn't be rushing to remove mine, seems to be a theory, but what are the consequences 🤔 surely Porsche or places like Hartech would recommend doing this if it had any benefit?

This ^ Hartech removed mine, Wayne Schofield made the necessary ECU adjustments / coding while mapping the car. I have had zero issues since it has been removed!