Need help folks

Discussion in '2005 - 2009 Specific Tech' started by Moseley, Nov 18, 2012.

  1. Greetings from Scotland.
    I purchased my 05 GT Auto in April 2010 and for the first 12months of ownership, she roared.
    This was my first V8 and the noise generated justified my choice and I guess, the stupid cost of fuel over here. She is fairly standard, other than a C&L and SLP exhaust.
    I should add that the engine check light was on from day one. Despite not having a reader, I was assured that this was due to the car running lean due to the C&L or SLP's(or both indeed). I have no reason to believe that the car had been tuned prior to my ownership.
    She sounded awesome, regardless of the speed. At times you were hanging on for dear life-I'm sure you folks know what I mean!
    Anyway, a year past April I needed a new battery. From the minute that battery went on, the car sounded garbage and lethargic. The roar went and really everything seemed like an effort, especially at low revs. Before,if you rev'd the car there was a roar/crackle/pop. Now it sounds more like a household "Henry The Hoover".
    The roar was replaced by a deep "farting" drone and despite everything I've tried, the frustration continues to this day.
    Oddly enough, at speed, say 70+ the noise and response is still pretty good and kick-down works fine.
    The battery was the correct one so I don't think that is the issue though I'll say again, the car was awesome until that day. I've done the idle test more times than I care to mention, the mass air sensor has been cleaned several times and the throttle body has been cleaned and now just this weekend been replaced. That didn't work either!!
    The car never came with a reader, so I got a Diablo Predator. I tried the canned tunes and they seemed to help but the deep farting drone still prevails.I appreciate that SLP's can drone at highway speeds but this is something else. I managed to get the C&L tuned in but I reckon the car sounds worse. Returning the stock air box makes no difference.
    Why have I lost my roar? Why does the car feel lethargic?I have no engine codes so I guess nothing major is wrong and fuel consumption is as it should be.
    The car is well serviced, fuel filters etc, but nothing seems to work.
    Ideas please.
    Thanks in advance.
  2. pull codes! They will tell you everything you need to know
  3. Do you have a smartphone? Theres code pulling apps. I use Torque pro for my newer obd2 cars
  4. Keep it simple Madspeed.
    Codes? You mean plug in my Diablo and look at trouble codes? There aren't any.
    I think what I need now is a list of possible issues so I can bite the bullet and just put the car in a garage and say "fix".
    I'm just wanting to give them some tips as I've exhausted my very limited knowledge.
    I know next to little about cars and everything I've tried I've picked up from the internet.
    Quite surprised myself. Who would have thought I could put on a new throttle body?
    Keep 'em coming folks

  5. i would lose the canned tunes and go back to stock. unhook the battery for 10 minutes, then go out and drive it for 20 minutes
  6. what c&l?
  7. Hi Madspeed,
    Other than "C&L" embossed on the tube I've no idea. "Racing" model perhaps-it has it's own air sensor.
    Re. the canned tunes, I've removed them and returned to stock loads of times in the hope that the issue would resolve itself.
    Also swapped the air intakes every so often.Still no joy
  8. ok, forgot its a 2005. That should rule out the maf then
  9. You need a tune for the C&L intake or it will run lean. Before you take it to a garage I would contact Doug at C&L Performance [email protected] and explain your problem. Doug is a great guy and he can send you some new tunes that should fix you up.

  10. Thanks Earl,
    I've sent an email to Doug.
    You would have thought that the issue would fix itself by running with the stock air box, but it's still running rough.
    Serious lack of performance and drone at low revs.
    I'll let you know the outcome.
    Any more thoughts would be appreciated.
  11. Almost sounds like whatever tune you had before disconnecting the battery, you lost when it was disconnected. I don't know how else to explain the car's personality changing with just a battery swap.

    You mentioned the check engine light was on, but now there are no codes? No codes means no check engine light (unless you have a reader unable to read all codes). If the light went out, did it go out with the changing of the battery?
  12. Cheers for the reply.
    I never rec'd a tuner with the car when I bought it and I have no idea if a tune was in it. I have always though not.The car had the engine light on when I bought it and the seller showed me a print out showing the lean codes 0174 (or something like that). I researched it and decided the codes were nothing to worry about.The seller had got the codes read by a local garage. So the car when bought had an engine light suggesting it was running lean due the C&L.
    After nearly a year of waking the neighbours, I changed the battery and instead of roaring, the car farts!!
    I have tried swapping C&L to stock box plenty times to date with little successs. I bought a Diablo and yes; the codes were suggesting the car was running lean. With the Diablo tuned in to the latest revision, I can run the car with the C&L and get no engine lights. Likewise, when I put on the stock air box, the car has no engine lights.
    So, the car runs crap but there are no engine lights giving me a clue to what the issue is to cause a farting, lethargic V8.
  13. Original spark plugs? If you decide to check one. Know not to just back one out. They are two piece and are famous for carbon buildup adhering to the insulator and breaking off in the head. There is a tsb which describes a procedure to follow which minimizes the chances of insulator breakage. Other checks might be to see if the charge motion plates at the bottom of the intake runners are operating ok. Aftermarket intakes usually require a tune so replacing the stock air box without also reinstalling the stock tune is counter productive.
  14. So 5 months later this nonsense is still going on.
    Got three tunes from Doug at C&L. Great guys to work with. Car seemed initially better though not great. After a while the car would go poor again; lethargic,unresponsive,sounding more like a hoover than a muscle car, really having to floor the accelerator to get any performance.BUT STILL NO ENGINE CHECK LIGHT AND NO CODES TO BE READ.
    Why would car initially accept a tune and then reject it a few miles later.
    What's the long time effects of running a car lean? With the C&L and no tune until recently, have I screwed up?
    I haven't changed plugs yet but surely if they were screwed I'd get an engine light?
    If my ECU was damaged, would that result in no engine light?
    She starts fine, idle is fine, no undue exhaust smoke-she just sounds and drives crap!!
    MPG is no worse than usual.
    Chaps at C&L are mystified. My car is a freak!!
    Over here in Scotland there are no mechanics with diagnostic machines so I'm really screwed.
    Need more clues chaps before I set fire to the bloody thing!!

  15. Well you wont want to hear this but I would recommend getting in contact with this guy, [email protected] This guy is a vendor at and has helped many guys with tuning problems but I'm fairly sure he only works with SCT software, so you would need to buy an SCT-X3. He can do the tuning remotely by having you make datalogs with the SCT X3. Believe it or not he is in Venezuela but he has remotely tuned some really fast cars on the S197forum, as well as helping lots of members.

    You may also want to check out the S197forum as it's the best technical information forum for 2005+ Mustangs.