I figured out that when I have a tune installed on my truck, there is a clicking noise when going right around 40mph. I noticed it also shifts sporadically once in a while. But when I uninstall the tune and set the truck back to stock settings, the click goes away, but the funny shifting still happens every now and again. I had the truck into the stealership for this issue and they replaced the cats (under warranty), and changed the trans fluid/filter, but it is still happening. What could this be?

 

I doubt it has to do with the tuner beings all the issues are still there when you are back to stock. Maybe its the stock shift schedule... did they check for recalls?

 

OK....where is the clicking noise coming from? Inside? Outside? Front? Back? Engine area? Does the clicking frequency increase or decrease with vehicle speed or engine speed or just click only when going @40? Does it click going straight or around curves? Define sporadic shifting....unintended shifting? Up shift? Down shift? Sometimes shifts into reverse for no apparent reason? You took it to the dealer for these same reasons and they replaced the cats? Did they say why and how replacing the cats would solve this clicking and sporadic shiftiing?

 

What he said ^ just give more details and we will do our best to help you out man

 

k...details...here it goes....I only notice the clicking at or minus a couple mph around 40...it does not matter going around curves or straight...i did notice it gets a little worse when towing...i took the tune off and it seems the clicking is gone, but still "shifts" funny to me...by funny i mean Ill be cruising at say 50 mph and the truck hesitates a little just for s split second and then back to normal she goes and the hesitation doesn't matter what the mph it is sporadic....the dealer said that the clicking was inside the cat and the "shifts or hesitation" could be caused from a malfunction in the cat....to me it sounds like a solenoid going bad (that type of noise anyways)... again I took the tune off and the click is gone, I have had the tune off for a few days now and it hasn't clicked at all....but the "hesitation or shifts" are still there....details on the "shifts" are that the truck does not actually shift gears or anything it just acts as though it slips out of gear for a second and then back in...to add to this also is that once in a while the trans will shift very very hard like someone hit the thing into gear with a sledge....I do not know enough about transmissions to know the internals of them, but I know that it shouldn't jerk the entire truck when it shifts up or down (I only noticed the very hard shifting on down shifts)...so this is the down and dirty on the truck....any advice is great...thanks guys!!