Hey all,
I need your thoughts on this.
Apparently the dealership said my car is running a little lean due to breather mods. (CAI/ Dual Exhaust/ Spacer)
Would those mods be sufficient to affect my A/F levels and why isn't my MAF adjusting for the changes?

That said what is the best way to fix this? I am assuming I will need a tune.
So what software and with who.

I was thinkng RCTS- Calgary, but is Lightspeed worth the drive?

Thanks!

 

Did you ask the dealership what your AFR was or how they knew it was lean?? These cars typically do run lean with breathing mods so maybe they are just throwing it out there based on that. My car ran lean I confirmed it with a wideband on the dyno but not lean enough to damage anything or even cause concern I even got an SAFC and leaned it out further. Typically there is power to be found in running lean, to an extent. MAFs only read air flow they can't change it. Your ECU can adjust but only so much, you are giving the car more air than it was designed to handle.

Where you are at mod wise I would say go to a dyno and do some base runs with a wideband and see if you have anything to actually worry about. Or get a COBB and reflash your ECU I think COBBs are worth $500+/- they come with a base tune or you can get a custom tune from a licenced COBB tuner.

As far as I know Reg (RTCS)only tunes F-cons (standalone ECU) that is not need with your mods and I know a few guys that use him but I don't know anyone that has a full tune they all seem to run only "base maps"

I am a Lightspeed customer and friend of the owner but personally I don't care if others use him or not. I always recommend him due to the fact he has at least 10x more experience with G35s than any other shop in Alberta and he tunes every ECU (he likes some better than others) under the sun. However good luck getting into get a tune he is booked for months in advance. You could buy a COBB from him put the base map in and go back later for a custom tune though. Another option would be a turboXS utec and anyone can tune it but they are more money and harder to install several members that have had them regret getting them and sell them and buy something different.

When I had similar mods CAI, Spacer and dual exhaust my car was on the lean side but not lean enough to cause concern I would bet yours is the same. Dealerships often talk out of their a$$es and have very little experince with aftermarket parts.

 

Considering my changes, this thread is making me nervous...

 

Not sure why It is well known that these cars run lean with any mods. If you add more air but do not add more fuel it will obviously be leaner than it came from factory. With minor mods it will likely not be lean enough to do any damage and if it dose lean out to much I think the factory ECU will pick up the knock and retard the timing. I have not been into N/A mods since 2006 now and even then I was researching FI mods and buying supporting mods for FI. N/A was never in my plan so i am not 100% sure on the factory ECU capability with knock detection and retarding timing but OEM usually do a fairly good job of keeping your engine safe. 1000s of people have the same mods most of you guys do and I have yet to hear of intake, spacer and exhaust cause a blown engine and like I said I leaned my car out further with an SAFC and I still never had any issues.

If you need peace of mind I think it is a few hundred bucks to get a few dyno pulls with an air fuel reading for peace of mind it might be worth it

 

Thanks for the info Gord!!
The only reason I am looking into this is i have had some idle issued previously, (looks like it was a bad ignition coil). But i am still having the car's idle drop at stop lights and hesitate. I'm going to clean the MAF again this weekend, but im not sure what else is causing this issue.

I didn't think that breather mods would cause me to run so lean the the car would just cut out!?

 

Everyone who wants anything to do with NA needs to look up Sasha Holy Fvck's thread on Ziptied. The stock computer can compensate for quite a bit.

http://www.ziptied.com/forums/index.php?topic=15975.960

Read. ALL OF IT.

Shaun (sp?) I dont think that breather mods would be causing your idle issue. Likely something spark or vacuum related is unhappy.

 

j/k, but I'll keep an eye on my fuel economy and watch for radical improvements (lol). Then perhaps an AWD dyno pull or two for kicks.

 

Thanks Hucker,
I've taken it to three shops (one being the dealership). I changed the plugs a couple months ago. One shop replaced an ignition coil. And no on spotted any leaks.

I am not sure what do do anymore..no one can seem to fix it. Just a bunch of expensive "try this" answers.

 

At this point I would shy away from Cobb:

 

Why would you shy away its not defective, just not profitable for COBB. I would buy one ASAP to be sure to get one. It is by far the best tuning solution availible in Alberta for NA cars.