My engine has been missing off and on when driving around town and also now on the highway. it seems to happen more when im in overdrive around 40-50mph. i now notice it does it at 70mph on the highway. my rpms will go up and down kinda like its not getting the right amount of gas. no codes are being thrown, and i checked all of the coils and i even changed the plugs. after the plug change it seemed to stop for a llil while but now its back. i was thinking maybe the o2 sensors are bad>? truck is an 01' with only 56000 miles on it. someone please give me some advice on how to get this resolved.

 

Read your fuel pressure and change your fuel filter. Read your pressure again to see the pressure change.

 

Got my miss cured( I hope) Was getting the code P0303 but the miss was sometimes gone.Dropped the truck off at one mechanic and he told me my head gasket was shot( Was never low on coolant,Didn't overheat or blow white smoke) and he said it would cost between 1400 and 2000 bucks.Said "NO",After re-replacing all the plugs and wires I still had the miss. Replaced the fuel filter then both coils still had a miss so I started pulling one injector plug at a time while the truck was running and found that ther was no change when I pulled # 2. Put a new injector in and she runs nice and smooth with no miss,So I guess I had 2 separate problems, A bad plug,wire,or coil and a bad injector.

 

thanks for your takes, anyone else have any solutions?

 

That's a weak COP . When there weak and at that point during any givin drivecycle you'll get load failure. That's the dead givaway it's the COP and nothing else.

Right after you shift into OD it will misfire.

 

I had a bad connection at the crankcase position sensor cause a similar problem on my 2002 SCREW with the 5.4L engine. No check engine light, and didn't seem to be associated with any particular cylinder, but felt like it was missing badly (shudder and no power). The cable going to the sensor was stretched so tight across the starter that it was pulling the connector apart. I disconnected the cable at the sensor, cleaned the connector, and re-routed the cable to the side of the starter so it had more slack. No more problems for the next 15K miles or so until I traded for my present ride. Any of these suggestions may be your problem - its just a process of elimination.

 

thanks! so i guess i will be looking into the coil packs then right? how do i test them to check if they are bad?

 

Put a little Mobil 1 5W30 on a rag outside your garage. It'll come back when it gets hungry.

 

That's pretty funny

 

 

Nah , you don't want "coil packs" - your truck doesn't use them. It uses COP's , one coil per cylinder..

Good Luck