ok so i added the following mods to my R56:

1-Magnaflow Cat back exhaust
2-Obx downpipe
3-alta intercooler
4-alta CAI
5-stage 3 alta tune

car was running fine until i got it dyno'd, it put out 165 HP! :S, obviously it was not right , so i sent it to mechanic and he said that the problem is spark plugs and ignition coil. so i changed the spark plugs and ignition coils (all brand new!) . and now whenever i try to go above 4000rpm the car hesitates hard !!! (misfire) so now he is saying the problem might be the cam sensor and crank sensor....i am thinking it might be the tune, because when i take out the tune, the car works fine, but also maybe because the tune uses a lot more boost...

Someone please help me !! has anyone had a similar problem to this ?
any help would be greatly greatly appreciated...

 

Try the stage 2 tune? Only because you don't have the 3" turbo back exhaust.

 

How's your carbon build-up? Any timing chain problems? How's your engine's compression?

-Charlie

 

Did you get a custom protune when you put it on the dyno?

Normally when you get a misfire code, it's either the spark plugs or carbon build up.

 

I have tried stage 1 , stage 2 , stage 3 all the same thing ! except when i take out the tune completely the car works fine.

the timing chain had a problem but it was changed 5 months ago, i dont know about engines compression or carbon build up.
the tune i got was from the AP standard 1-3 and i also tried the custom tune that, i think you or jeff made im not sure.

 

How many miles are on the car? If it has a good amount of miles, you will want to check for carbon build up.

What can happen is since our maps are more aggressive than the stock maps, you can run into issues if the plugs are not gapped correctly, or if the valves are dirty with carbon.

 

It has about 38 thousand miles on it. I will double check the carbon buildup just in case ..

 

i had something like this a while ago and all i needed was new plugs. i had less miles than you too.

 

did you put in OEM plugs, because i put it in aftermarket platinum tips.

 

Just FYI, i've heard to go OEM with plugs. They're the best out for our cars as of now.

 

i heard that too, but i said go aftermarket since most of the modded are aftermarket :D

 

OEM plugs.
my car is a S with a JCW tuning kit, RMW flash tune, Alta FMIC and Riss Racing catted DP. the issue never happened when i first got the tune and also never happened with stock tune. then after about 5 months with the tune it stated happening but still wouldnt do it with the stock tune. i knew it wasn't the tune since it didn't happen when i first got it. after i put in new OEM plugs it was all good back to normal.

 

Only use OEM spark plugs on the R56! All the aftermarket plugs cause stupid problems like this. Everyone that has drank the aftermarket spark plug Kool Aid for the R56 MCS ends up $60 poorer and forks it out again for the proper NGK plugs.

Second, find a new mechanic that doesn't have you blindly throwing parts at your car without proper diagnosis

Cobb has a good article on what you should check before hitting the dyno. Yes, it's aimed at Subaru, but it's still very comprehensive on what things you should check before spending your hard earned cash on the dyno.

http://www.cobbtuning.com/Technical-...es-s/70675.htm

 

When Alta tuned mine, they gapped the OEM plugs to .018" and they still had about 40K miles on them. At 51K they were shot so I changed them to a colder range and kept the gap at .018" --- still running great. Colder plugs are not recommended unless you have a significant HP increase, as posted elsewhere.

You might try different gapping to resolve your problem. Out-of-the-box gapping is seldom good enough.