'16 STI - OEM Up Pipe Flexible?

[OhThatHurt]

Kind of a noob question... Does the OEM up pipe have a built in flex coupler?

Background - Today I removed my EL header to have it thermal coated. After I removed the header I bumped the bottom of the OEM up pipe and it moved a bit. Seems there is about 1/4 in of movement if I push/pull gently sideways. All bolts on top are tight and there are no signs of soot. No CELs, boost issues, or exhaust leak noise, so I don't think it is cracked. Is a slight amount of movement normal?

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[undyjr]

Yes, there is a accordion like flex connector under the heat shield. In my situation my factory up pipe developed a split in the flex connector. I attempted to braze the split with my oxy acetylene rig and %56 silver bearing solder. The metal is just too thin. Without knowing if this is a typical occurrence I would plan on replacing it when most convenient.

[OhThatHurt]

Originally Posted by undyjr

Yes, there is a accordion like flex connector under the heat shield. In my situation my factory up pipe developed a split in the flex connector. I attempted to braze the split with my oxy acetylene rig and %56 silver bearing solder. The metal is just too thin. Without knowing if this is a typical occurrence I would plan on replacing it when most convenient.

Thanks for the feedback. I did find confirmation of the OEM flex connector in the uppipe FAQ. The car only has 8K miles. At this point I think the movement I found is normal. I had not detected any leak or unusual sound before removing the header.

When your UP developed the crack what were the symptoms?

[undyjr]

The initial symptom has hissing/whooshing sound during WOT. Comparing datalogs in particular the lower WGDC showed a pre-turbo exhaust leak. After torching off the heat shield (kinda sketchy, not recommended) and using an inspection mirror I found the 1 inch split. Without a doubt extended periods of WOT fatigued the flex joint. If you never go WOT past 4th you'll probably be ok.

[Unabomber]

Uppipe crack = loss of PSI and/or noise...lots of new noise.

[OhThatHurt]

Originally Posted by Unabomber

Uppipe crack = loss of PSI and/or noise...lots of new noise.

@Unabomber I am pretty sure the movement is normal and nothing for me to worry about. I did not know the OEM uppipe had a flex section on it. It kind of freaked me out that I could move it a little bit. Learning as I go... I did not notice any unusual noise or boost loss before removal of the EL header. I happened to get some logs just last week for my tuner (BrenTunung) to review MAF scaling before I removed the header. He did not indicate there was anything unusual.