Okay guys, I've tried everything. I have an 2012 G37S Sedan, My problem is when I cold start it'll die if I do not give it gas.. When I drive I can feel the lack of power.. Doesn't have the same " Get-Up". It was giving me MAF code.. I cleared it. Replaced the MAF's and no change.. Even went to dealership.. they say my stillen GEN 3 intakes are pulling in too much air & to put on my splash shields to restrict air with my mesh grill .. also I have no mufflers/resonators at the moment .. back pressure? Tune? The dealership updated/reset ECU, as well as did a idle reset.. No change. Help needed thanks

 

Helps to know what codes were being thrown - would narrow down the troubleshoot. I JUST installed my Gen 3 and had MAF issues and was able to solve the issue with Surf **** and Bnewt's help. Here is the link:

https://www.myg37.com/forums/general...nce-these.html

I think there ended up being a vacuum leak in my case. MAF sensor wasn't reading the air properly which resulted in codes being thrown. I simply, loosened my fittings, readjusted everything and made sure they were snug and then cranked the clamps like my life depended on it and boom - codes gone and car is happy.

ALSO, make sure you put the MAF sensors back into their corresponding intakes. If you switch passenger to driver or vice versa you will throw codes. I actually did this on a bulb change and my car had very rough idling similar to yours.

 

Did you replace with OEM MAFs? I know on my older VQs, they were very picky about MAF sensors (and of course Nissan is highway robbery for OEM). Also just had a similar problem on an Acura that turned out to be throttle body gunk. The electronic throttle body tries to open the plate slightly at idle, but if there is carbon blocking the airflow, it will stall. I haven't heard anyone else with a Stillen Gen3 having this issue with no other mods?

 

No other mods in my case. Unless we know what the codes were then it's a little hard for us to troubleshoot.

 

That's true. But that was really a vacuum leak, in my opinion, so not related to the intake (only the intake install process). I see what you mean, though. Always hard to troubleshoot via keyboard, but doesn't stop us trying

 

When I had my MAFs switched I experienced similar issues as OP. You're right, mine was a vacuum leak but in that thread I mentioned my MAF switch. My car never died like OP's but my Tach was quite bouncy until I switched back and reset the ECU

 

It was giving me P0171 system lean bank 1 which can be a ton of things, but when I used the Reader at autozone .. it came up on there cpu as Maf sensor.. can an OEM MAF & AFTERMARKET MAF be the problem????? I may have cracked the case lol

 

In other words I'm running 1 Aftermarket Sensor & 1 Oem Sensor.. could that be an issue?

QUOTE=MNoriegaG37s;4112899]It was giving me P0171 system lean bank 1 which can be a ton of things, but when I used the Reader at autozone .. it came up on there cpu as Maf sensor.. can an OEM MAF & AFTERMARKET MAF be the problem????? I may have cracked the case lol[/QUOTE]

 

Try cleaning the throttle bodies?

https://www.myg37.com/forums/engine-...0174-code.html

Exact same code and after cleaning them the code went bye bye. I can't speak about running an after market and an OEM but I wouldn't think there'd be a problem. Try cleaning the MAF and TB - then worry about a MAF replacement.

 

Switch MAFs from each bank, and see if the code also switches banks.
Cleaning the throttle body is a VERY good idea, usually the aftermarket intakes remove the oil/air separator allowing quick build up. If they are really dirty, you will need to do a "idle air volume learning" procedure to drop your idle back to normal.

By the way, your intake can not "pull in too much air", it is the throttle body and valve lift that determines how much air flows in the intake.

 

Thinking this might be the case. Sent that link to you and decided to do myself and my TBs were filthy