When I had a loud header to cylinder head leak somewhere on my 87 Mustang GT, I took off the vacuum line from the brake booster and submerged it in some Seafoam (suggestion from Mustang site on web) while engine was idling. This produced smoke in the exhaust and immediately showed where the leak was. I then drove for a few miles before the smoke cleared out from the exhaust. At first acceleration, I looked like the space shuttle taking off (smoke from exhaust pipes).

Steve

 

Well took this long to get it fixed, it just got worse over time. Flex pipe was replaced with aftermarket braided solution, no more noises.
Hopefully the visual smog inspection won't be an issue here in CA. By the way, dealer wanted $1600.00 plus labor to replace the entire
cat. Insane.

 

Smog inspection went OK. So if its help to any CA folks reading this later, I guess if they aren't sticklers you can get away with the flex replacement and not having to do the whole expensive CARB approved one piece cat/flex replacement. May seem silly to people outside CA but we deal with a lot of BS here. Yes we will probably retire somewhere else. LOL

 

Glad it’s fixed and it passed!

 

GM dealer in Garden City, MI quoted me 1800.00 said they would have to scrap the catalytic converter to fix it. I’ll try a muffler shop.

 

California has very strict laws about catalytic converters, so don't compare any other state. A dealership can only replace parts with parts made by the car maker, they do not repair parts. Unless you are seeking warranty work there is absolutely no reason to go to a dealership for repairs.
There are many alternative fixes for a cracked flex pipe, if it was still under the 8 year/80,000 miles federal emissions warranty they MUST replace the catalytic converter as a complete assembly from GM for free. In some years GM had longer emissions warranty than required by law.

 

Yes that is insane and well worth just replacing the flex pipe portion like any sane state would allow. My guess is you will be able to find a smog station that will
not be a stickler to that nonsense as we did. Its not a mod, it does nothing to increase emissions, it extends the life of the catalytic converter. It's a repair.
Take it to your normal smog station that has seen the car before and I wouldn't even mention the repair. I doubt they will care if they even notice.
Expecting people to pay nearly two grand for a simple flex pipe issue isn't acceptable and sometime we just have to find a work around.

 

Michigan has no smog stations, so no worries. We replaced a flex pipe on our Traverse earlier this year. A Muffler shop sleeved and welded a section in for $120. You should be able to find an independent to do that for you, too.