Hey guys, I’m having a problem with my truck I cant figure it out I’m stumped. My truck when I come to a stop about 10mph and down clutch in and on the brakes it wants to cut down to 500rpm or less, it also sucks a lot more gas. I put it on the code scanner comes up with a code 45, thermactor always up stream. I took checked the plastic lines for the thermactor air divider and the thermactor air bypass solenoids lines are good. I put thermactor solenoids on from another 5.0 truck just to see if it was the solenoids they didn’t help even tried ones from a mark7 lsc H.O5.0 to see if it would know they weren’t the right ones but still same code. Then I took off the valves off (the plastic deal with the 3 rubber hoses) they both hold vacuum. If I plug off the plastic hose going to the divider it will sit and idle fine coming to a stop but it has a delayed reaction on acceleration. Has anyone ever had this problem before I can’t figure it out I don’t know what it could be or what to do, I was told it could be a false code for the o2 being out of range im puzzled on this one HELP. I just had my new exhaust done with the headers, and all the check engine light was on for a day but it went out before I could get it on the scanner so I figured the o2 was dirty or something like that but now I dont know what to do .

Thanks
Curtis