I have had this 05 hemi 1500 for a few years it's been good but I'm really frustrated with the crappy throttle. I couldn't spin the tires if I tried. Fuel mileage dropped from 13mpg with a heavy foot to 7mpg with driving like a granny.

I have tried these things-

-cleaned throttle body
-replaced throttle body
-grounded throttle body
-replaced IAT sensor
-replaced MAP sensor
-inspected and cleaned PCV
-removed, inspected, tested and reinstalled EGR valve
-replaced plugs
-replaced entire exhaust system and cats
-replaced fuel pump twice

The only thing that made a noticeable difference was replacing the fuel pump a second time. Original pump died. I replaced it with a crappy parts store pump. Only was putting out 35psi at idle. Second replacement pump helped a lot. However the mushy throttle pedal has been around long before I had any fuel problems.

Any help would be appreciated.

 

What brand fuel pumps did you get?

 

Precision for 26gal tank

 

Have you done a compression check, leak down check?
You can check head gasket by removing radiator cap on cold engine, then start the engine. If you get bubbles through radiator cap then head gasket is bad.
What is your rear end gearing, do you have anti-spin differential?

 

How old are your O2 sensors?

 

I haven't done a compression test yet. I can do that today. Rear gear I think is 3.50ish. Just seems like its throttle related still. Could it be the accelerator pedal itself? Is there a way to test it? Do not want to just change parts without diagnosing if I can help it.

I did hook the truck to a scanner with live data stream. At idle it said throttle was at 12. Dont know if this is normal or not. Load was 20. Front o2 sensors kept bouncing from .9 to .1 to .6.

I pulled o2 sensors to check for plugged cats and they all looked light brown like a spark plug. Previous owner did say it has gone through multiple o2 sensors trying to get rid of the CEL. Since the last time they were replaced a couple years ago I dont think its tripped the CEL. There was an EVAP code but it's been gone for a while.

 

Ok. I pulled all 16 plugs then put 8 back in and did a compression test. All the plugs except one looked good. The secondary plug on cyl 3 was loose and black. The plugs have been in a year and look good. Light brown in color.

Compression was between 135-160 on 7 cylinders. The back cylinder on the driver's side I was fighting the brake booster so I dont think it was 100% tight. It read 120.

I also found that the EGR tube was loose from when I worked on it.

I drove it around the block after and it feels the same.

 

What plugs are in it?

 

NGK I think. The color on them looks like they're burning good.

 

Just bought 2 upstream o2 sensors. We will see if that does anything. I doubt it but why not at this point.