Buckcommanderf150

My truck idles rough when its idling. It does it in park and in gear. When I slow down, the rpms dip real low and it occasionally dies. Would a tp sensor make it idle rough? I've replaced 4 of them in this truck but it never idled rough, it would just idle low when they went bad. Its real bad when I first start it. Any help would be greatly appreciated!!

udderbrudder

A TP sensor is unlikely. Infact I don't remember ever replacing one. Usually a TPS code is a result of a sludged T-body. I'd be looking at cleaning the IAC and the T-body. Also check for vacuum leaks.

Warspite

Any codes popping up? Could be a bad misfire as well. First, look for vacuum leaks as Udderbudder suggested. Especially the hose from the PCV valve to the rear of the throttle body. If the elbow is crushed, chances are there's a hole there, as well as the root of the problem.

garbill2003

Theses guys got it start with the cheepest then work your way up. Unless its giving you a code

Buckcommanderf150

Thanks for the tips!! I looked at the vaccuum lines and they are all good. I have a true dual exhaust system and I noticed that the drivers side smells like rotten eggs and the passenger side smells normal. I'm thinking there's a misfire on that side but I just replaced all my plugs and wires so idk why it'd be missing out. Its not throwing any codes either

tan_1

Do you still have the cats? Sounds like a plugged cat on the drivers side. Also check that your MAF is plugged in fully, mine came loose once and caused it to idle all over and die out.

Buckcommanderf150

I just had all my cats replaced with magnaflow high flow cats and ill clean that maf sensor real good and post back!

raif281

my trucks doing the same, I havnt figured out what's causing it either

BrowningSCrew

Mine was doing that last year it was a plugged fuel filter and 2 bad plugs

Buckcommanderf150

I just took my plugs out and cleaned them even though they are only a month old and I tested both coil packs and they are good. Checked the maf sensor and cleaned it and still no luck.