Unplug the front O2 sensor(s), see if it runs any better. If not, physically remove them from the exhaust, and try again.

 

ok going out right now to give this a shot will reply back in a little bit. If u dont mind looking me up on Instagram I'm on there ashttps://instagram.com/duck_allen?igshid=ZDdkNTZiNTM=. More of direct messages I've been dealing with this for weeks and almost got fired last Friday cause the truck won't run right. I appreciate ur help truly

 

I don't do instagram.

 

Ok well update disconnecting the upstream 02 from the wire harness did the trick on getting the truck to be able to do hwy speeds but fuel efficiency and power is still dog**** in 1st 2nd and 4th gear still Hella biggest down but does not die or buck. I'm thank the y pipe me with me 2 work 2morrow and gonna fix all the welds and seal any holes other then the O2 upstream witch in a couple months when I can afford the cheap catbac and the glass packs and hookers. And re do all of it. Thank I so much man I can go to work tomorrow night thank u.

Any suggestions on the no ***** and bogging in 4th???

 

Is the cat plugged up??

 

No cat was stolen b4 I bought the truck

 

How many miles on it? Blown plenum will effect power/fuel mileage..... also oil consumption. Low fuel pressure will give you some odd behavior under load....