Hey everyone, im new to the forum but i have a few questions to start with and see if i can get some help.

First off, iv got 75,000 miles on the truck, and when i lean into the throttle and the truck shifts out of the overdrive gear i get a hard thud, it sounds like the gears are hitting one another extremely hard. But it will not do it any other time, only on the downshift from overdrive to the lower gear.. to my knowledge the trans oil has never been changed.. however it has good color and doesnt smell burnt and has the proper amount. any ideas?

Number two, iv got a rust hole in the muffle, in the interest of saving money i was thinking i would hack the stock muffler off, buy a magnaflow for 50 bucks or so and use a clamp to put it back on.. then from there reroute the tail pipe to exit in front of the rear wheel because the aftermarket mufflers are not nearly as long as the stock.. anyone done this? will it affect performance and gas mileage negativly?

Third, the truck has stalled 2 times when cold, i took off and go to the stop sign at the end of the road when the truck stops so does the motor but like i said this isnt common but it has done it.. i dont know if this is related but when the truck is warm ill come to a stop and put it in park and the idle surges up and down between 500rpm to 1200rpm rapidly, sometimes it wont stop until i turn the motor off or blip the throttle?
thanks in advance for any help

 

1. mine does it too. but mine has 265k on it. dont worry about it until it slips.

2. anything is better then the stock muffler. im running no muffler, and i have a little more power judging my butt-dyno and i also got about 2mpg increase after i unhooked my battery and let the PCM reset.

3. the IAC is bad.... replace. call it a day.

 

sweet thanks for the reply.. were do you buy your aftermarket parts?

 

either JEGS or summit racing. summit racing has a lower shipping cost, depending on where you live.

 

thanks man

but would a trans fluid change do any good.. i thought 70,000 miles what about time to get that done..

 

go for it. i mean, it couldn't hurt. it'll only hurt your wallet haha. and remember, dont get freaked if theres a yellow or green plug in the pan. thats a good indicator that the fluids never been changed.

 

on my 02 f150 with the 4.2..i just put on a flowmaster super 44 i got from advance auto and also a 18 inch 2 1/2 straight pipe to extend it to the same length as the factory muffler so the tailpipe doesnt have to be adjusted..... only complaint i have is i thought the flowmaster would have had a lot better sound, but it sounds stock yet in my opinion (sidenote: does anyone know of a good LOUD muffler??)