Good luck with getting a Borla muffler replaced like the cat back system I purchased new. Was later told the muffler design had a design problem.
I wasn't "the only one with this failure problem" I was later told by daddy Borla not the kid John Borla as seen on TV.
Sounding like a gallon paint can full of rocks heard me coming down the street rattling 200' away outside, yes that loud not alone the constant inside rattling noise while driving or shifting gears. A 95 D1 5-speed.
Battle with John Borla going nowhere lasted 4-5 months with several phone calls to Borla going nowhere. It wasn't a cheap item purchase.
Was told "you found that muffler in the wrecking yard and trying to get a new replacement free".
I mentioned I had a warranty card of a million miles, John Borla's reply, "anyone can make several warranty copies off a copying machine".
Yeah right when I also have a credit card receipt plus an automotive parts supply store invoice copy of my Borla cat back purchase from them in their records. Automotive supply store was nice enough to also sent Borla a copy of their records showing my cat back purchase from them.
Getting nowhere with John over 4-5 months time calling then one day daddy Borla answered the phone.
Told him what was going on for several months after several phone calls.
Was told "the inlet / outlet muffler pipe to internal pipe connection had failure problems with several mufflers", so I wasn't "the only one having a failing Borla muffler problem".
Daddy Borla wasn't too pleased on how I was treated by John Borla.
Had to credit card order a second muffler direct from Borla (Southern Calif.) for my cat back system with "the newer improved muffler design" shipped directly to me. Once received return the defective muffler for a credit back to my credit card account.
Was later told after calling Borla,"your in our computer file system should you have any future cat back including muffler system failure problem and still covered by a million miles".
Yeah right so easy to hit the delete button then I do not exist.
Note, original defective muffler outlet or inlet stub side (?) has a short piece of pipe 2 1/8" OD x 2 7/16" long slipped inside the muffler stub then fusion welded around the two edge circumferences.
This hour glass shaped insert has the center ID reduced down to 53% of the cross sectional area of the exhaust pipe entering the muffler or only 1.540" insert ID. How can a 4.0 or 4.6 litre V8 engine's exhaust breathe through a 1.540" single exhaust system restriction and make horsepower pulling a 4,600 pound empty D1 I ask? Excessive back pressure and unwanted extra engine heat added to these borderline overheated engines.
Told this restriction was to increase back pressure increasing low RPM torque.
Replacement muffler did not have this muffler restriction just a normal inlet /outlet design.
My engine is much happier without this exhaust restriction in the 4,500 to 5,500 rpm range without any low rpm torque losses.
If I wanted a restrictive overweight, silent strangling engine exhaust system I would of left the factory system alone and not shelled out money for a Borla cat back stainless million mile system.
Nope I don't think so.