Multiple P codes

[Dubchevy74]

I got P0740...P0785...and P1860. 2004 trailblazer ext is in REP mode (limp mode). Changed fuel pump a week ago thinking my sender unit was bad. But it wasnt. The fuel guage still read empty. Put an aftermarket guage in and popped the j case 32 fuse which is a trailer fuse. My truck reved up high and went straight into reduced engine power. The codes that were thrown were originally were P0222...P0223...P2122...P2123...P02128. I replaced the TBS and APP sensor...both u have to buy as a whole unit. I can only start my truck from jumping the starter. I still have no throttle response...my wife is about to rip my head off. I need some help.

 

[Mooseman]

Try disconnecting the fan clutch. Sometimes when it goes bad or has a short, it throws the 5v reference circuit out.

 

[aaserv]

I think also the Throttle body sensor will have to go thru a relearn which can take a little while. Should be some other threads on the site here that will help you with that as Im unfamiliar with the 6cyl but I know its been discussed many times. If you completely disconnected the throttle body when working on it thats almost assured to be a problem. Hope you cleaned it while it was off as that could have been the whole problem from the start.
I sincerely hate throwing sensors at a problem because now not only do we still have problems we also have new parts that we dont know if they are any good.... New doesnt always = Good..