Yesterday I took my honda civic Si (1997) to a muffler shop, where they told me I needed a new catalytic converter as well as the front end of the muffler. I opted to go for an after market part, rather than a genuine Honda part because of the cost. Well...now the muffler is making a god awful noise and I sound like an F1 racer. So..I took it back to the muffler shop, who said that the catalytic converter they put in (despite what they told me yesterday) was not compatible and it was reverberating with the back end of the original Honda muffler - and they said they would fix it. However, fixing it may mean taking off the Honda muffler and replacing it with a piece of crap that is compatible with the new catalytic converter. So - anyone know if the 1997 Si needs a particular type of after market catalytic converter (i.e. they put the wrong thing in) or should I just go with a genuine Honda part ? Or should I let them replace the 10 year old Honda muffler back end with a new piece of crap? Any informed suggestions welcome.

 

Does your aftermarket converter actually have catalyst in it? Or is it one of the ebay ones that is just an empty pipe?

I'd start by blocking the tailpipe with the engine idling to check for any leaks. You may just have really lousy workmanship at that shop and now they're selling you a snow job.

Generally when the B pipe (from the converter back to about the back wheel) becomes rotted out, the stuff in the back will not last much longer either.