exhaust disappointing
 

I just put the cat-back exhaust (Gibson) on my truck this afternoon and it doesn't really sound any better or louder, is that normal? I have a '99 250 w/v10. I paid $250 for it and was expecting a lot better sounding exhaust. The power does seem a little better but it still revs up high before shifting into 2nd and 3rd though. Any ideas fellers?:confused:

Exhaust won't help your shifting. You will need a valve or programmer for that. As far as the sound goes, if you put a catback system on it isn't going to be that much louder than stock. It will have a little beefier sound but is tame so that the in cab noise isn't to bad. About all you can do is change the muffler for a "race" muffler. IE Flowmaster 40 series.

It sometimes takes a little bit to get the muffler opened up.
I know Flowmaster 2 chambers get a little louder after a few miles.

I also put a single Gibson on my 03 V10, I was also dissapointed. I've always had flowmasters, don't know why I thought the Gibson would be comparable. (fell sucker to the advertising)

So I left the cat back on and swapped the muffler with a piece of straight pipe. It's a liitle loud but I like it. Probably go with a FM 40 series in the future. The only good thing is I still have the original in one piece so I can switch back if needed.

If you want loud get rid of your cat.

I know, I know, I'm the devil don't waste your breath.

if you lose the cat will it throw codes or run too lean/rich?

nope

Mine runs way better without it (V8). And I have scanned for codes and it throws none.

What you are describing only happens on vehicles that have O2 sensors downstream of the cat and even in this situation MIL eliminators are all that is needed to correct the signal.

Might check that out.


We do have yearly emissinons test here. I would have to rig my stock exhaust to include the cat and bolt in back on for the inspection.

What muffler are you running?

i did the gibson thing on my 99 v10, and it sucked. replaced with a 50 series flowmaster and the thing sounded great (for a v10).

I am running the 3 chamber flowmaster and it is plenty loud. I have the 2 chambers on my mustang it is lounder but the tone is not as deep. I prefer the 3 chambers on a truck.

Also fitting a pipe in place of the cat is super easy and can be swapped in and out for warranty work or emissions testing. The back end of the cat has a slip fitting so that is convienent. The front end you will need to cut. I used a band clamp from jcwhitney to connect this end. Works like a dream.

does it sound deeper/more big blockish with the cat out of the system or just louder? I have a fm40 on my v-10 but it just sounds "semi-loud and raspy" vs. the "loud and deep" tone I'm looking for. I know its possible because I was at a red light with a v10SD that was loud and deep (admittedly with the v10 indy rythem) but it really sounded sweet. The only thing I noticed was long chrome (like 18-24") exast tips that got bigger in diameter (like 2 1/2 inch expanding to 4 or maybe 5 inches at the end). it sounded like it had a lot of grunt and got deeper sounding as he accelerated through the RPMs. Mine sounds semi deep at idle but just gets... raspy-er at higher rpms. I'd kill to know what the guy did to his exhaust to get that sound.

it defineltly deeper at idle and lower rpms but does get raspy at higher rpms. I think the deepness of the sound is more related to the muffler used. Headers will help with this too. I don't think exhuast tips do anything. I bet the guy you are talking about had headers, not cats, and true dual exhaust no cat back.

Anfo, he probably wasn't running a Flowmaster muffler which is why it sounded deeper. Take a look at Spintech mufflers if you want a deeper sound.

Why would a Flowmaster sound better?
 

The Gibson muffler (along with the cat-back kit) is a straight pass type with not internal restrictions. Has baffles lining the inside of the pipe. Why would a Flowmaster sound any better when the Gibson has no restrictions? I would ditch the Gibson muffler and put on a Flowmaster in a heartbeat but see no reason to yet. Any thoughts? Could the cat be plugged up, and how would I see about checking it? Thanks guys.

The cat is easy to check. The material inside is of a honeycomb shape. You can readily see through the honeycomb passages. It is quite obvious to tell if its stopped up just by shining a light through one end and looking down the opposite end.