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      01-04-2013, 12:43 AM   #1
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Drives: 09 335i 6mt
Join Date: Oct 2007
Location: NYC / Bay Area/ Park City/ Pittsburgh

iTrader: (21)

Need Help! Downpipe-midpipe studs broke; misfires; hiccups/stutting...Suggestions?

Hey guys, well i just picked up a CPO 09 335i and i just installed a AA exhaust. However...While removing the stock exhaust one stud/bolt on each of the pipes broke. I cut the studs flush to the flange and ive tried everything to get it out...(heat + Pb blaster + hammer + Air gun). I don't want to risk damage to my turbos by persisting to force them out. I need suggestions.

Heres my problem, each dp-midpipe is being held by one stud/bolt on each pipe. I KNOW it is leaking but, it doesnt sound like it is...Ive been driving it around with my exhaust as is and ive been recently experiencing misfires in cylinder 5 on two occasions on one day leaving a SES light...AS well as hiccups/stutters in 3-4-5 gear going from 2k rpm- 3/4 or wot.

So i took out my JB4 and UR Cold air intake, cleared the codes and the hiccups/stutters are gone, and no misfires so far. I'm a but confused about the hiccups and how they are now gone, i was almost sure that my intake valves need to be cleaned and that was going to be a problem regardless. Perhaps may b my car was poorly adapted with the jb4 and cai with the exhaust leak, which in turn would cause misfires?

-At this point, i need to take it in for servicing to get plugs/injectors/coils and what not looked at also because im due for a 30k service. I'm pretty sure the exhaust leak isn't the culprit, but do you think that BMW will notice the missing two studs on the downpipe and perhaps blame the exhaust leak for the misfires and the hiccups i'm experiencing?

***So, first i need any suggestions about the dp stud issue, shops? what kind of shop? Options ?

as well as

*** suggestions on if i should take in my care to BMW for servicing w/ 2 dp studs missing with misfiring problems and 30k service...Anybody suggestion that i dont take my car in with an exhaust? I did ask my sales manager, but he mentioned a cat back was okay...but he kinda sounded confused because i mentioned the 2nd cats, but he was like yeah, removing those will throw codes and what not...But i think he was refering to the o2 sensors on the primary idk, haha.

Thanks in advanced, and sorry if you need clarification for anything just post up.