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loss of power

4.4K views 56 replies 6 participants last post by  lkoroush  
#1 ·
I have a 04 gt 6spd I've seems to have a loss of power I have ssa header straight piped with dc sport baffle mufflers other mods are spyder cai with spectra filter not sure if I should use the stainless steel mesh filter but also have lightweight flywheel and stage 2 clutch along with ngk blue wires and ngk G power plugs gap is .040 and the intake spacer
 
#4 ·
Well I wouldn't expect you to lose a terrible amount of low end torque but it is a possibility. When you try and accelarate hard what RPM are you at usually? Also, you should feel a lack if power around 5.5k RPMs but that is because of the stock upper intake manifold.
 
#5 ·
Should I regap my plugs from.040 to .044 and was thinking about replacing the straight piped where the resonator was with my flowmaster super44 that way I'll have some backpressure since I don't have any
 
#8 ·
When I look at pretty they around 14 not sure what my stft are what else could cause loss of power and also I just put the new ngk G power plugs in and now it idles around 900 Roma and when in neutral and I rev the rpm will have but like I said no vac leaks
 
#14 ·
Ideally LTFT's are "0", but the ideal never happens. Usually +/-8% is fine, the bigger the value gets, the more likely you run out of ECU adjustment.
Big numbers can indicate an issue (mechanical or electrical) or a leak.

Is it "+14" or "-14" on the LTFT?

Also, I wouldn't use a different plug gap than spec.

How long ago did you install the CAI & headers?
How long ago did you do plugs & wires?

Did the "loss of power" happen right after work was done to the car, was it later & sudden, or later & a slow decline?
 
#15 ·
Here are some pics of torque app and we'll spec for gap is .039-.043 so I figured to .004 will make a bit bigger spark, I felt it lose a little power as suspected I would after headers I replace the SRI for the CAI and felt better results and I had the eBay 10.2 racing wires then put the ngk blue wires and for me I felt it got worse then once I went from ngk iridum to the ngk G power lost more power
 

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#17 ·
Since it doesn't say + or -, I will assume it's adding fuel which means the ECU is seeing it lean.

How do you know you don't have an air leak after the MAF? That would be a good reason for the ECU to add fuel.

Still didn't answer when this happened or how long the new parts have been on the car.
 
#18 ·
It is + I've had headers since last September,the CAI since around march,the wires since May the plugs only couple days and I know I don't have a leak cause I used MAD cleaner I had and spray all the seals and nothing and also my vac gauge is 22 steady also I forgot to add that my rpm are fluctuating and when car in neutral and barley tap the throttle it will go up to 2.5k and sit and sometimes right after start up it will go to 1k drop to 500 than go back to 1k
 
#19 · (Edited)
Dude that sounds like a vacuum leak.
With just headers and an intake your car probably shouldn't have 18% LTFTs either, I would expect more like 8-11% as normal.
And.. You gapped to 0.004? Or 0.040??
 
#24 ·
In post 14, I stated, "ideally, LTFT's would be "0""....... a bit either way is usual, before you reset the ECU you were getting close to maxed out.
 
#22 ·
Also since I don't have any cats or resonator and it's all straight piped do you think I'll get a little needed backpressure if I put a super44 where the resonator was and to help get rid of the raspy noise
 
#25 ·
Ok but even thou it is better like I ask what I get little more power and the super44 so it has a little bit backpressure I know letting it breath is better but I think the setup I have now is robbing some power
 
#26 ·
You DO have vacuum leak. It may not seem obvious at first but if you look around carefully, for example, the rubber pipe from the MAF to the throttle body, you will get it. You will have to REMOVE this pipe & check it carefully, especially on the underside of it.