Active Fuel Management

[RickGM]

AFM (dropping on to 4 cylinders) is only included for those of us with the L99 engine (V8 Auto). There's pages of complaints on the main (US) forum about how crap AFM is. I must be missing something coz I can't tell when it's kicking in and when it isn't - no apparent engine noise difference and no lack of instant grunt when you floor it. Does anyone else notice it?

[ShadowV8]

Yeah, it's horrendous!

When I first got the car, being like me I always had it in M or 'sport' mode and didn't fully notice it. However, since using D mode I notice it a lot more now, and when you have the back boxes removed or any other exhaust mod it sounds like a diesel engine when it drops to 4 cylinder. The large centre box/ muffler after the cats is responsible for masking the change as much as possible, but when you know what it sounds like you'll know when it happens and it'll drive you nuts!

It can be removed though

[#737 ZL1]

Originally Posted by ShadowV8

Yeah, it's horrendous!

When I first got the car, being like me I always had it in M or 'sport' mode and didn't fully notice it. However, since using D mode I notice it a lot more now, and when you have the back boxes removed or any other exhaust mod it sounds like a diesel engine when it drops to 4 cylinder. The large centre box/ muffler after the cats is responsible for masking the change as much as possible, but when you know what it sounds like you'll know when it happens and it'll drive you nuts!

It can be removed though

Yea I need some help with this issue also. Have a 2012 2SS auto convert that I just put the corsa 14964 cat back system on. Car sounds awesome but when in drive and just leaving a red light or stop with light acceleration you feel the car shift than jolt a little like the A/C or defrost just kicked on and it goes into this low over drive mode with a low drone. Never had this happen with the stock system or maybe just never felt or heard it only when I upgraded exhaust on this car. I hate to reprogram the computer because its not a car that I race, just an everyday driver. Any ideas guys. I almost want to put that stock exhaust back on and let it sound like a street cleaner. I'm sure this has been discussed in many of threads.

[RickGM]

Yeah that accords with what others say on the US forum - horrible noise when it drops to 4 with "muffler delete". They seem to recommend a tune to completely remove AFM or the Range plug in to the OBD to eliminate it. The latter seems to have all sorts of issues though.
I honestly can't tell the difference though and have used manual (which knocks it off ) and Auto which turns it active. Maybe the resonator nullifies any issues while you run the car stock.

[cam62]

I notice it and it's horrible. I have the range device. (March of this year). Best money I have spent in a long time.
I can only speak to my exeperience. I have had one instance of an issue that was cleared by a restart of the car.

l99 in drive or m mode AFM is active.

[RickGM]

Originally Posted by #737 ZL1

Yea I need some help with this issue also. Have a 2012 2SS auto convert that I just put the corsa 14964 cat back system on. Car sounds awesome but when in drive and just leaving a red light or stop with light acceleration you feel the car shift than jolt a little like the A/C or defrost just kicked on and it goes into this low over drive mode with a low drone. Never had this happen with the stock system or maybe just never felt or heard it only when I upgraded exhaust on this car. I hate to reprogram the computer because its not a car that I race, just an everyday driver. Any ideas guys. I almost want to put that stock exhaust back on and let it sound like a street cleaner. I'm sure this has been discussed in many of threads.

Check this out - 42 pages though. Disable AFM for $200 but there are issues.

http://www.camaro5.com/forums/showthread.php?t=283175

[jules1200]

TBH this is pretty much the reason I hunted around a bit to get a manual, I didn't like the idea of the 4 cyl. jobbie

[RickGM]

Originally Posted by jules1200

TBH this is pretty much the reason I hunted around a bit to get a manual, I didn't like the idea of the 4 cyl. jobbie

I'm in for an exhaust job on Wednesday (see After Market Exhaust thread) and if the switching to 4 becomes obvious, which everyone says it does without the stock exhaust, then next job is to tune it out or buy the Range device.

[ShadowV8]

Originally Posted by RickGM

I'm in for an exhaust job on Wednesday (see After Market Exhaust thread) and if the switching to 4 becomes obvious, which everyone says it does without the stock exhaust, then next job is to tune it out or buy the Range device.

Steve SS can probably tune it out for £100, along with loads of other issues so speak with him when it becomes an issue. I'm living with it for now but soon to have headers replaced which WILL make it worse so I'm having it tuned out. It is still there in M mode just less often.

[RickGM]

Yeah I remember a pm from Steve regarding his Diablo Intune.

BTW, if your replacing the headers don't forget that Apex vid at the start of the Exhaust thread. That car sounds SWEEEEEEET with its set up.

[ShadowV8]

Originally Posted by RickGM

Yeah I remember a pm from Steve regarding his Diablo Intune.

BTW, if your replacing the headers don't forget that Apex vid at the start of the Exhaust thread. That car sounds SWEEEEEEET with its set up.

I can't afford more imports at the minute, so I'm going with custom fabrication cat back instead for now