My R/T does that too. It is fairly common when gearing down and most
noticable with a loud muffler.
> Subject: DML: Cat Back 'back firing'
>
>
> Well I installed my 40 series flowmaster single in dual out cat back on my
> 4.7L last night. I love the sound (whoever said 40 series is too loud, is
> just too old!) but when down shifting or letting off the throttle around
> 2000 RPM there's that annoying gurgling and backfiring sound.
>
> Has anyone else had this problem? Is there a fix for it?
>
> I had it on my '88 Mustang 5.0L and fixed it by removing the air pump
(pumps
> ambient air into the exhaust to 'lower' emissions ... what was happening
> there was the fresh air was burning with the unburnt fuel in the exhaust
> pipe ... remove the air and there's no more burning).
>
> Anyone? Please help, cause I hate that sound! I think what it might be
> doing is actually sucking air back into the pipe when I let off the
> throttle.
>
>
> thx.
>
> --
> Canuck
> --------------------------------------------
> Y2K 4.7L 2wd 5spd
> http://www.twistedbits.net/WWWProfile/dakota/Vyikam1jjgNN6
>
>
>
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:05:06 EDT