It's entirely possible that the intakes were more firmly secured at one point and then loosend up a bit resulting in more movement than there had been initially. Likewise, something could have flown up and damaged the exhaust.

On that note, any pending codes? You might want to see if autozone can scan the ECU for you (or pick one up).

It's strange... i'm interested myself in finding out what it winds up being. OP, have you attempted to snug any of the exhaust bolts down yourself or clamped down the intake pipes a little more? Is there any sort of rough idle that might give the indication of a vaccum leak? If you have a friend that can get in the car and rev it a little bit, you can mix some water and a little dawn in a spray bottle and spray all around all the areas where things are clamped and see if there are any bubbles that come from any of those areas... you can also do the same with your vac lines, it could be maybe something small like maybe even a cut in the vac line or silicone tube for that matter.

some people will use a starter fluid around those areas sometimes too, if you hear the engine suddenly rev up a little bit under idle, you likely have found your leak. It's been a while since I did any of that stuff though.

One other question... are the pipes on with a worm type clamp or T-bolt clamp?

thanks guys for all your input so far. as to the clamp question, I have worm type at the throttle body and t bolts for the rest. I have some extra t bolts that Im going to install at the throttle body just to make sure everything is clamped securely. I'm going to look at everything this weekend and see if I can find out if there is a leak somewhere. about the idle, it seems to idle smoothly but sometimes idles a little rough. the thing I notice the most is when the car is warmed up and idling the revs will drop a little then go back to normal. idle doesn't bounce around but drops slightly then goes back to normal. it's also not the fan kicking on either because the fan doesn't come on when the revs drop. hope this makes sense.

I removed both of those pieces of plastic on both of my 370's and never had issues with the MAF.

hmmmm.... I haven't been around my car while it was warmed up and idling to see if it does this, so i'm not sure about it.... i'm to cheap with gas lol. It's always possible though. How many miles are on the set-up since everything was installed?

There is also the chance the mechanic damaged the MAF sensor when doing the install. Not like most people are going to be honest and pay 200 or however much those things are to replace it.

Don't forget to check all those dumb little things like that the MAF is plugged back in and such... any other wire you see, follow it, check it for breaks, burns, obviously being unplugged, etc etc.

2000 miles on g3's, 500 with both g3's and exhaust. like I stated before, car ran great then overnight took a **** on me. hasn't run well since.

Yeah, that's so odd. I really think the issue will wind up being a MAF sensor going bad or something along that line, but hopefully not.

that would be ok with me. I just don't want my problem to b a mechanical one where it's going to need warranty work.

My G3's don't move around a lot. The right side intake is really secure and the left has a little more play. I used a dremel to route out the stock holes so that intake pipe could fit through. If they took out the stock plastic pieces and put your intake pipes in I could see them having a ton of play. That's weird though that you had them installed at Stillen and they deviated from their own instruction manual on how to do the install. Hmmmm...

Shouldn't happen. If anything you should feel a difference after putting the intakes in.

you think a tune is what I need? I'm going to look over everything tonight and try to find anything that could b out of the norm. I just want my z running tip top, I love my car.

The tune would be needed after a while, but there is no reason why the car would not run much better with an intake and exhaust even without a tune.

agreed

well, I fiddled with the intake clamps and found a couple that didn't look like they were tight enough around the throttle body. so I tightened them up and moved them to get a better seal around the piping. car seems to b driving quite a bit better. I will reserve judgment until I put a few more miles on her but this may have been the problem all along. so anyone having similar issues this may b your problem.

I thought you had tightened them more already?

I tightened the other clamps near the maf sensor. I was waiting til the weekend to mess with the other clamps and replace them with the spare tbolts I had.

Another way you can check for vacuum leaks in the intake tract (PCV hoses, etc, aside from the main intake tubes and throttle bodies) is to spray something volatile like starting fluid nearby the suspected connection with the engine running. If there's a vacuum leak the engine will suck in a bit of the aerosol starting fluid and you'll hear the idle speed change from the mixture change. Just be careful about how much you spray, hot metal surfaces, etc. You should have a fire extinguisher on hand in your garage anyways :)

^^ the next step if the car keeps running strange. thanks for the heads up;)

Man, I remember doing that for hours when I had a boost leak on my Evo... I sprayed a little and thought I found it and then do it again and it wouldn't work and on and on... SUCKED!

it really does suck. had a msp3 and had to do the same, was very tedious and time consuming. I'm really hoping I don't have to do it again for my z.

at least there aren't as many hoses and such. We have an 09 MS3 as well.

ms3, most underrated car on the road. I loved the torque in that car, stock for stock would roll sti's and evo's no problem. went from that to the z:)

I actually came from a '10 MS3 myself with an SRI and a COBB stage 1 tune. I agree the power is underrated. 4th gear REALLY pulls hard... a shame that turbo is so small and dies off at 5500 though.

I had 07 true red ms3, Cobb Sri and stg 1 ots tune. great car, I just had too many fuel pump issues. had to get rid of it for that reason. replaced the fuel pump three times and it still never was right.

those plastic things (aka stock air intake ducts) are meant to be removed. it's impossible to fit the intake properly without removing them.

the core support is supposed to be trimmed with a tool of your choice, to accomodate the circular piping which is wider than the existing holes which are exposed once the above mentioned ducts are removed.

if the holes have been cut too big, there is no choice but to fab up a bracket for each side or wrap the piping in rubber sheeting or EVA foam. Stuff like a camping mat is perfect and cheap. I'm surprised they cut so much out that the pipes are that loose. i hate loose things in my engine bay so when i fitted mine, i cut the holes to leave about a 5mm gap around and i wrapped the pipe with EVA foam to absorb vibrations. You'd want to also make sure there is adequate protection for the a/c lines on the left side as the G3 is known to eat those pipes over time if insufficient protection is installed. All you need is to cable tie a rubber hose over the section of ac line (slice is lengthways and push it on).

cheers

a little late there buddy. ^^