just wondering if anybody with an exhaust temp gauge has seen a drop going from stock exhaust to 4". also temp with no cat as well. thanks

I had a definite drop in EGTs when I cut out my factory muffler and spliced in a Magnaflow straight-through 4" muffler into the OEM pipes. I had installed my pyro prior to the "mufflerectomy" and EGTs dropped 100 to 150 degrees "across the board" in every operating condition. Oh, my '01 never had a cat.

I will let you know when I get my Truck... I have the Edge Juice w/ Attitude sitting on the bench ready to install (it has an EGT gauge). My truck should be here the first week in May. I am going to take it step by step recording my results along the way. A few blocks from the dealer, I plan to unplug the EGR valve, get home and install the EGR plate, Fingers stick, and Juice w/ attitude. I will leave the stock exhaust on for a while, then remove the cat, then install a 4" exhaust. Sorry I don't have an answer for you now, but from what I've read, it's good for a 150-200 degree drop.

I put on 5" and I've dropped egt's 200-250 degrees across the board. I have a muffler and my cat disappeared.

What benifits if any have been gained by going to an aftermaket 4 inch and leaving the cat? (Metalhead I'm not trying to hijack your thread, just get more info) Thanks,
Rick

you'll see at least a 200 degree drop in temp with complete exhaust change. with just front pipe and stock muffler you'll see 20-60 degree drop.

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