BrandonsBlueStang

Hoping someone can help me with a very frustrating problem. I got my 2007 GT in April. It was 3 hours away, I drove there once to test drive it, a second time (with a mechanic) and test drove it again and after no problems were found we brought it home that day. We stopped for gas and I put 91 octane in and I didn't know what tune was loaded on it so I decided I'd load the race tune on there to drive it home. The next stop as the car got to low RPMs it started rattling like crazy, we turned the car off and started it back up and it was fine. We got it home and I started doing research. The rattle was very common and would happen every time I let the car get too low of RPMs, the only way to stop it is to turn the car off or rev it to over 3k RPMs. The car also had a CEL on [Code: P0345 camshaft position (cmp) A ckt (b2)] After a lot of research I decided to replace both camshaft position sensors, didn't fix the problem. I also read the rattle could be caused by a bad alternator so I took it to O'Reilly's and had the alternator tested. Sure enough, bad alternator. I replaced the alternator almost sure that was the issue but sadly, it did not fix it. I've decided because we drove the car so much before we bought it (20+ minute test drives both times) that the problem started when I loaded the race tune on there. I tried returning the car to stock and it will not stay running. It idles anywhere from 500-1500 (fluctuating without touching the gas) and will hardly rev up, you have to put the pedal to the floor 3+ times to get it to rev to 2500 RPMs. The mods (that i know of) on the car are: JBA LT Headers, Steeda underdrive pulleys, O/R H pipe, Borla Stinger axle backis, JLT Cold air intake. Out of these mods I don't see why the car wouldn't at least run with the stock tune on there (even if it had a CEL on). I'm working on uploading videos of the rattle and the car trying to run on the stock tune. Any help is much appreciated and thank you to those of you that took the time to read this.

JJHoover

try putting the stock air box on it when you return it to the stock tune

BrandonsBlueStang

Unfortunately I don't have the stock air box, it had the JLT CAI on already when I got it

Nuke

Start with the little things. Clean the TB (is it the stock TB?), replace the fuel filter, clean the MAF. What kind of shape are the plugs in? Are the COP's OE or aftermarket?

dlazrael

So, I was having wierd idle issues whenever I came to a stop, depressing the clutch the car would bog down to as low as 250rpms, and stalled once every 100 or so stops. It was worse if the stop was sudden while accelerating. I pulled the TB off and cleaned it really really good, fixed it for a little while, cleaned the MAF, again fixed for a little while, yesterday I blew out the air side with seafoam... seems to have fixed it for now.... I'm hoping to figure this out before I put the blower on (hopefully danzcools!)

Also, the stock tune most likely wont work at all with the aftermarket CAI, there is a reason they all say tune required. Try loading the base tune in from the tuner as opposed to the race tune.... Just an idea. Also could try the 'hard reset' of d/c the battery >30 minutes to see if it can reset how the CPU "remembers" the car driving......

bigblue95z

Can't use a 'stock' tune on a CAI'd car. Will run terrible. Get a hold of a reputable tuner that can tune to your device. There are reviews all over the boards on which are good, which are sketchy....

MustangVixenGT

I am betting when you test drove it, it had already been custom tuned to what it had. By putting a 91 octane tune on it, it upset the car then putting it to stock just upset it also. Just out of curiosity did the tuner and the tune come with the car or was it something you already had. Because every car has to be tuned a bit different.

lawrencecar1

is there a "street tune" that you could try ??

AK_Kayaker

Maybe the gas you put in it was bad.