Just glad you figured it out OP.

 

How many miles were on the car?

 

just hit 52k miles. bad news though, after changing all the plugs, its still misfiring. needless to say the car will be at the mechanic tomorrow. i dunno what else to do. ive taken the 93oct tune off the car and set it back to stock, cleaned the TB, MAF sensor, air filter (before cleaning MAF sensor) and ofcorse the plugs. im assuming its the coils but im at the end of my rope and ive givin up on the DIY path (usually never happens but i cant take any more disappointments). im just praying its the coils and not something major like a bad valve or something.

any ideas? i ran the car about 3-4 miles with it running fine and then the idle went back to being sh!tty and then flashing check engine light. i went from being EXSTATIC to being disgusted. im glad it car atleast STARTS so i can get it to the mechanic but still extremely disappointed that i just couldnt get it done in my driveway.

 

Trace back to when it was last running correct. What happened between running correct and running bad?

Are you throwing codes? If so, which?

 

just dropped it off at the mechanic and before i left the keys with him i checked what codes were coming up. still getting P0174 (even though i cleaned the MAF sensor TWICE) AND now im getting P0305. Looked that bad boy up and says its misfiring on cylinder 5. now im just hoping that when i went to start the car without that hose connected and it started up and stalled that i blew that one plug because i did rev it once and it knocked HARD! so hopefully its just plain stupidity on my part when it comes to that p0305 code and its just a fowled plug. now as far as the MAF sesor code goes i dunno . could it be possible that ill need to replace the sensor?!

the car seemed sluggish a few weeks ago, almost like it was struggling to breath. so i cleaned the throddle body top to bottom and the car ran like a top again. thats when everything started happening. the check engine light went on so i cleaned the air filter. took the light away for 5 min, came back (code p0174). so now i clean the MAF sensor...still getting P0174. so i change the plugs and here i am. like i said, i just hope its nothing serious like a blown valve or something. i cant afford that right now AND tomorrow i plan on leaving for Lake George, NY for a few days with my girl. luckily she has a very dependable car but all my $ cant go to the car right now!

 

Just to add to the discussion, I had a similar issue this week. I took my car in for an oil change, and when I left, I noticed it was idleing funny. I stopped at a redlight and the RPM's were going up and down by about 450 RPM. Turned out the oil change place had checked my air filter (stock) and never clamped the airbox back down. I guess air was getting by causing the surge. Good luck with your car, and let us know what you find out!

 

P0174 is a lean mixture code... do you still have a vacuum leak somewhere?

 

allll fixed! my mechanic changed the coil that was on the original fouled spark plug which i changed earlier. he called me up and said car is ready, come and get it. i get down there (skateboard down there hahaha), ask him if he drove it to test it out and he said yes he did. so i pay the bill (charged me 112 for the coil and 90 in labor), take the car around the block, it starts idling horrible again and the check engine light begins to flash again. so ofcorse i bring the car right back and tell him no-go. he hooks the car up and it is throwing the P0305 code again. this time he busts out the stethoscope and starts listening to the engine to hear any sort of knock or ping. well he puts it up to the injectors (after i suggest he do that) and says the injector which is above the coil he just replaced and above the original fouled spark plug sounds like it isn't "even opening" (his words not mine). so i said ok lets replace that injector! 2 hours later i skateboard back up the garage and this time its running like a TOP! also he didnt charge me a dime for the labor on the injector and i took back the original coil that he also replaced.

on a side note, he asked me if i "chipped the car". i said well i did have a 93 perf tune on there but i put the car back to stock approx 100 miles ago. he said 90% of the time when someone brings a new(er) car up to him and it has the same type of issues i had it is because the car is or was chipped. even though i told him i know plenty of guys that have a custom tune on their mustangs with no issues he assured me that was the cause of all my problems.

what does everyone on here think? for now im running stock but the slow throttle response and lack of instant agility that i have right now is driving me NUTS! i def forsee the tune (from brenspeed) back on the car in the not so distant future hahaha.

 

I have ran a tune on my '06 since the day I got it, so have many others. Put your tune back on and enjoy it!

 

Not laughing at the situation that led to it, but the skateboard part and the visual of someone riding one down to pick up their Mustang really cracked me up.

 

should have specified longboard but yea i could see how that would be funny hahahaha

 

leave the tune on, thats just a part that went bad, would have prolly went bad without the tune... dirty fuel prolly caused it to clog and break. You may want to run some injector cleaner in the tank..

 

injector cleaner is the FIRST thing i did when the car started acting weird. like you said, prob some bad fuel messed it up. even though i think ive only put brand x in the tank less than 5 times since i got it back in the summer of 06

 

I thought the V8 heads were changed in 2008 Job 2

 

Yep. Started in Dec 07 - which was Job 2. Bullitts were Job 2, and mine was built 1.9.08. Brown plug boots (vs black) are the new design.

 

Hose get you everytime man, be careful!
Boy am I glad I got the new heads, build date 1-28-08.

 

The pesky vacuum hose.....or as I call it the sea foam intake hose