Problems installing new Exhaust system

[joezek]

I just had a few problems with my muffler shop. When I dropped it off he told me he would cut off the rear cats no problem, and run 2 pipes into my dual in/single 3" out muffler, and run a 3" tail pipe from the muffler to the back bumper.

2 hours later the guy calls with a major attitude saying the rear converters are NOT going to be removed because it will destroy my mileage, torque etc.

He also said it's impossible to run a 3" pipe over the rear axle, it's not going to happen, he won't do it etc. So he reused the stock 2.5" tail pipe and connected to the new muffler with 3" outlet.

I thought the 3" tail pipe was done a few times by you guys? This is on a 2003 model, maybe it doesn't fit?

 

[Fanatic1074]

I just installed a flowmaster system and its a 3" pipes all the way back. Mine is the 03 5.4L 4x4. Sounds like your exhaust man is being lazy or something.

 

[joezek]

Yeah he was bein lazy. I went to another shop and the guy was eager to install it the way I want it. He's ran 3" pipe over the rear axle before and said it's just tricky, you gotta know your shit.

He also said no problem deleting the rear cats, just warned about the loudness. - BUT he had never seen a Spintech muffler as big as the one I ordered, so the noise shouldn't be bad. He says spintechs are LOUD, but everyone gets the smaller ones on their cars. I got the longest one (22" I think) so it would be quieter.

So far I'm extremely happy with the unique deep sound of this muffler. It's like it was designed to cancel the high frequencys and only let the rumbling V-8 sounds through it. I had 3 chamber Flowmasters on my Pontiac for 10+ years, and honestly the Spintechs blow them away (just my opinion, no offense to you FM guys).

Now when I cut the rear cats if its too loud I may end up putting in a Flowmaster 70 to quiet it down a little more.

 

[joezek]

Update

I got a different shop to delete the rear cats for me today. Not only did they do like I asked and delete them, but they showed me how ALL the welds from the previous shop were extremely sloppy, and the previous shop didn't coat the welds with enamel to help prevent rusting.

I'm very glad I had the rear cats removed, and definitely satisfied with the results. It's perfect- quiet idle, deep gutsy sound at part throttle/acceleration, crisp/racey sound at high revs, and awesome sound on the highway. You can definitely hear it at 70 mph, but only if you turn the stereo off.

MPG gains: initially my mpg gain didn't exist because I can't stop revving it up just to listen to it. However my standard test on the highway using cruise and trip computer revealed a 2 mpg increase. Over time the results will average out and I'll know for sure if it's definitely an increase or not. However I will point out that for the last year I've never gotten a consistent 20 mpg at 71 mph with cruise set, and today I did for over 5 miles. The last 6 months I've been cruising at 65 mph in order to reach my 20 mpg. Now at 65 mph I get 22 mpg.

Overall it's appears to be a win/win situation and Charlie Sheen would be proud.

PS: muffler guy #1 initially agreed to remove the cats, then backed out stating that on this engine the mpg will be "...cut almost in half by removing the back pressure of the rear cats..." and also said it would lose all of it's torque. Well I'm here to tell you he doesn't know WTF he's talking about, torque hasn't changed a bit and MPG appears to be better. I'm not the only one on this site to have the same results!!!!!!!!!