I took my car to a local performance shop to have my 4-1 header put on. After a few hours of work i was told by the mechanic that i needed a flex pipe put on in order for the header to bolt up underneath. He said to take it to an exhaust shop and tell them i need a flex pipe put on at the same my header is put on. As anyone had the same trouble?

Edit: The car is a 98 Integra GSR

 

No, if it's a quality built specific header it should be a bolt on affair. A header install should take 30-45 min. with jackstands and handtools. Look the merge pipe - it should have an o2 sensor bung for the 98+ integras. If no bung then you have a 94-07 header which is shorter.

 

94-99 GSR exhaust manifolds are the same with no O2 bung in them as both are in the cat. 94-01 LS and 00-01 GSR have a longer A-pipe and an O2 bung in the collector.

The header won't need a flexpipe unless the spring bolts where the header and cat meets are eliminated.