badwithcomputer

I fear I may have a cat that's nearing clogged or broken up. When I go full throttle I hear loud successive pops sometimes two or three in a row. The truck has been down to Ford and the Master Tech had it out and said the readings on the downstream differ significantly from on side to the other. Everything else checks out. No engine lights but a misfire on 7 and 8 which only the computer picked up. I replaced the coils yesterday which solved my hesitation but my back fire remains. It's also always felt really sluggish but I attributed that to me being used to my old '11 with a 5.0

Engine is 5.4 3v

I want to check the pressure in the upper o2 sensor on the offending side, what's is the spec? I did find one reference that mentioned 2psi so I just wanted to get another opinion or 3.

Thanks!

Hunter Brabham

Do you have an aftermarket muffler? I took my muffler off to put a new exhaust on but I ran it without a muffler for a little while and I don't have much back pressure so it was slugish, got bad mpg, and it popped a lot��

650NutKase

Looks like you answered your own question. Universal cats are cheap and easy for a muffler shop to put on.