In a nutshell my piping from the pre cats to the y-pipe are off by .25"..The left piping is 2.50" and the passanger side is 2.25". Y-pipe, cat, muffler and the rest of the piping is a 3" setup.Canthe piping being off by .25"causeunwanted back pressure? Whichis causingtemp gauge to risemore thannormal at idle,then go back to normal operating temperature once I startto accelrate again. Just asking sincethe aftermarket y-pipe that was added which was made by the muffler shop was recently replaced with one from magnalfowwhich thenI noticed at idle the temps dont rise as much before. Maybe pointing at 1:00 at the highest than 2:30ish with the custom y-pipe.. Just about everything has been replaced on my truck, t-stat(went thru 2 of them), radiator flush, radiator cap, radiator,hoses,coolant temp sensor and aftermarket high flow third cat. Added an electric fan which did not help the situation one bit. All this was replaced before the magnaflow y-pipe. Could it be the pre cats are going bad or just the piping size causing this or something else? Not loosing any coolant either. Need some help on this.


[IMG]local://upfiles/2103/736BB85150334E13A2D7D6EE8A38F612.jpg[/IMG]

 

that shouldn't be doing anything. weird.