Code P0300

No, I did take it out and made absolutely sure that it was free and clear of any carbon buildup. Replaced the gasket. I will try to disconnect it tomorrow and take it for a spin.
Wayne

OK, just returned from the test drive. It might have made a very slight difference. Hard to tell. In 2nd gear still bucking and coughing a little with and without hooking up the EGR valve. In 1st gear at 15mph you get one hell of a ride. Coughing and jerking like you wouldn't believe!

New for me, how do you check for the back pressure?

I can order one on line that has an adapter that looks like it would fit in where an 02 sensor goes. May take a few days to get it. I was wondering if my compression gauge used on the cylinders would work and have the proper adapters?
Wayne
PS: Were you referring to run the engine no higher than to generate 15 lbs of compression or 1.5 or? I thought that there was to be no compression if the Cat isn't plugged. I also noticed that on youtube that had that problem. The vehicles couldn't get power, where mine had no problem getting to 70 mph. Open throttle and it flys.

Ordered gauge. Due here around the 1st of Feb.
Any idea of what else to check while I am waiting? I would hate to go after a compression test on the engine. Everything is so hard to get at on this truck.
Wayne

Roy, How are you on 2001 Ford Expedition vacuum line routing?
I have a disconnected hose and do not know where it plugs in.
Should be easy, but I just can't find it.
Let me know. I have enclosed a couple of photos just in case.
I think I have the white hose correct, It is the red one that I can't find a home for.
They both come out in a harness from the passenger side of the engine around back to the driver's side.

Wayne