What did you do with the old mufflers?
Sent by a dumb ass with a smart phone.
Andy..
You might want to keep your stock type muffler. The replacement of the hot-rod type mangaflow with the pickup OEM type aftermarket replacement muffler has made some positive changes....which I think are from increased back pressure...allowing the 02 sensors to work better.
(1) more responsive power
(2) better civilized engine behavior (no backfiring, no popping in the exhaust from deceleration or from down shifts
(3) observed better fuel economy...have not had time to really check it on the road but appear to be doing better
I don't have any emissions controls and only the front two 02 sensors, PCM is stock tune as far as I know regarding power
I like the new muffler a lot, less noise, more responsive engine..no observed bad manners from the engines/exhaust.
Old muffler dual in dual out 2.5 large magnaflow, new muffler large OEM type aftermarket replacement...3inch in...dual 2.5 out. Running a magnaflow y at the front of the muffler to bring both pipes from exhaust into the muffler, then dual 2.5 out from rear of muffler. So far good experience....can tell from "seat-of-the-pants" better response. Due to exhaust popping and minor backfires from old muffler I'm sure engine was running a little rich, also my assumption that new muffler increases back-pressure and this has a positive impact to the 02 sensors operation and thus the PCM controls the engine more efficiently.
I drove the truck around a good bit this afternoon on the road to see how it runs....never got over 205F on long hill aggressive driving and was smooth and good running...not really connected to the muffler thing...but certainly no observed backfires or exhaust popping.
THe other positive impact is that the sound of the exhaust is not over-bearing.... I hear the tires and other noises now, exhaust is only noticeable on acceleration.
