• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

Gibson 2.5" single cat back on a '94 4.0


GoMopar440

Well-Known Member
U.S. Military - Veteran
Joined
Jul 19, 2012
Messages
52
City
Anaconda, MT
Vehicle Year
94
Transmission
Manual
My truck came with a "custom" exhaust that was installed by a previous owner. It had a flowmaster muffler with a single inlet and dual outlets, and the tail pipes were routed through the spare tire area and out the back to either corner. I wasn't a fan of this setup for a few reasons.
1) The tail pipes appeared to be 2.25" and were compression bent, causing them to act like smaller pipes as far as flow is concerned.
2) The routing of the pipes hit quite a few places under the truck causing a lot of creaks, rattles and banging when driving. Not to mention, I can't haul my spare unless I want to just leave it in the bed, which I don't.
3) Lastly and most importantly, it sounded like a ricer fart can when I would upshift. You know the sound. Kinda like a bumble bee on crack bouncing off the insides of a tin can. It would have been really funny if it weren't coming from my truck.:annoyed:

So I started researching my options here on TRS and other places on the web. I settled on a Gibson cat back 2.5" single side exit system. I took it to a local shop that had a good rep and had them install it since I wanted it welded in rather than using the supplied U-clamps. I also wanted them to weld a flange on the existing mating pipe. The old system was welded together at that point for some reason.

When they pulled the old system out, I could easily see why it sounded like crap. About 2/3 of the front of the Flowmaster muffler was split open at the weld. The two tail pipes that came over the axle were also welded together with a piece of 1/2" metal rod. The entire 1"x3/4" welded area ripped out of the pass side pipe. I'm sure the broken hanger on the tip of the pass side didn't help anything either.

The new system went in pretty smoothly. It got welded at all the junctions except where they added a flange. Everything lined up with the factory hangers The broken rear hanger was also replaced. The hanger wires were able to move around in the rubber hangers a bit too much so washers were tacked onto the hanger rods to hold the pipes in place better. The tail pipe tip was also tacked on in a few spots. That way if the pinch bolt ever got loose or fell out the tip would stay on the tail pipe.

I didn't get any pics of the old exhaust, but here's a couple of the new setup.
102_0755.jpg

102_0754.jpg

102_0756.jpg

102_0753.jpg


So far I have to say it sounds 100% better. It has more of a deeper rumbly sound but it doesn't have even a hint of droning on the highway. It's definately a quieter system overall compared to what was on it before. It would probably be louder than a 100% stock exhaust, but not by too much. It's got a little bit of a rumble to it, mostly at idle and when taking off from a stop. I don't have any kind of dyno to go by, but the seat of the pants feel tells me that it's about the same power wise.

I also got some Pacesetter headers to install at the same time, but I didn't like the cheap looking cardboard gaskets that came with them. That and the paint that comes on these headers isn't a high heat paint. It's just enough on there to prevent rusting till it gets to the customer. Uhhh...:icon_confused: would it kill them to spend a couple of extra cents to squirt some actual header paint on these things? I'll be repainting them with either header paint or cerokote before they go on so I don't have to pull them off later to fix any rust issues. I've already picked up some Bosch OEM replacement O2 sensors for it so I don't have to try to pull the old ones out of the rusty exhaust pipes that are on there now. I also noticed an extra hole in the rearmost driver side down tube for the EGR system. It's not too rusty, but I hope it doesn't give me any headaches when the old manifolds come off and the new headers go on. The new Y pipe is a two piece unit, but I'll have it welded together once it's fitted into place. I'd rather not use the supplied U-clamp as they never seem to hold until they've rusted themselves on. Here's a pic of the headers (and crappy gaskets) FWIW.
102_0757.jpg
 
Last edited:
I have been running the Gibson on my Explorer now for a few years and haven't had any issues at all with it. I didn't add headers, but I did put a high flow cat in when I had it installed. Its amazing how a new exhaust will change so much....
 
GoMopar, I think I have the same Gibson exhaust coming in the mail. I'll also be installing JBA headers. I thought the JBA Headers came with the piping (y-pipe?) after the collectors in the headers but apparently not. Where did you get yours? Any tips on the header install?

BLOODBANE, what high flow cat did you get? Was it a bolt on or did you weld it in?
 

Sponsored Ad


Sponsored Ad

TRS Events

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Ranger Adventure Video

TRS Merchandise

Follow TRS On Instagram

TRS Sponsors


Sponsored Ad


Sponsored Ad


Amazon Deals

Sponsored Ad

Back
Top