As the photos illustrate, my downpipes look very strange.

I expected to see either cat material in the downpipes, or not see it. I didn't expect what I got.

The back downpipes on both side have the cat "filler" stuff at the top of the downpipe. The front downpipes both have the filler several inches down, and it's partly folded over itself, which I wouldn't think does anything for the exhaust flow.

Is it just coincidence that both my fronts have had the filler pushed down into the pipes? This is clearly an unacceptable condition.

Thanks,

John
1987 XJ-S V12, 62,000 miles

 

I ripped all of that out of mine when I gutted the cats. I can't believe they don't cause a significant amount of backpressure and loss of performance.

 

Get rid of this stuff thanks god they did not put it in our Aus spec cars. Anyway put the cats further back mine are now located behind the transmission. Will only effect cold emissions once the cats are hot they work normally.

 

Gutted my converter, both front and back and could not be happier. These *******s cause major issues and might even set your car on fire. I also wrapped downpipes and converter cans with heat wrapping tape, which takes away tons of heat from under the hood.

 

It's a pre-heater for the old-tech cats. My right bank was clogged and a hole had been burned through the pre-heater on one side. Yours is just farther gone.

Let's just say my car breathes more freely now.