i have a 2006 hemi mega cab I put a y pipe right where the down tubes bolt on to the rest of the exhaust in at a local exhaust shop and cut off the very rear resonator shortly after i got the P0420 catalyst below threshold so exhaust shop says need new cat bank 1 drivers side so they threw in one cat worked for a few miles code p0420 back on i tried the no foul on drivers side behind new cat now i get p2096 bank 1 post catalyst fuel to lean i swapped left and right o2s same code on bank 1 so im sure the o2 is ok can someone help me fix this or sell me there stock down tubes with working cats or point me to some cats to weld in im sick of seeing this cel for something stupid and living in new york i cant pass inspection due in a few months any help would be appreciated

welcome to the site.

all non foulers should only be on the rear o2s

as for the front o2s, check for pinholes in the exh and leaking exh manifolds from broken bolts. what happens is they leak sometimes and suck in fresh air which screws with the front 02s. with you living in NY where salt and sand is laid, id look really good

Sorry i did not clarify both codes are for the post cats the front ones are fine i am thinking to just go back to stock because the dealear wont warranty the exhaust now that i cut into and installed a y pipe post cats that is why i did the cat at local shop the truck only has 50,000 and its a 4x4 hemi mega cab nothing else has been done to it i am just having trouble locating the stock down tubes and cats except through the dealer and they want a hefty sum for stock down tubes and cats if i am going to pay that money i could put on an aftermarket header downtubes and cats as far as holes in the exhaust i just moved here from north carolina so i dont think that is the roblem i dont see any soot or other signs of leaks do you think not having the very rear resonator could cause this or is it still a cat issue im sure they popped the cheapest cat possible in . thanks for the help and if you know anyone selling the stock downtubes and cats i would love to purchase them that way i eliminate anything and can get the dealer to warranty

I've done the non-foulers about a half dozen times and never had a problem, BUT I've never done them with a cat, always for a cat delete. I can't see where just basically moving the O2 out of the direct stream is gonna generate a CEL though.

Just for sh*ts and giggles, check around the manifold for a broken bolt...

I checked and nothing is broken just a check engine light showing i guess i will try a salvage yard and see if i can get the stock down tube and cats then i can take out the y pipe i had welded in and put a new flange on for the rest of the exhaust that way i eliminate everything i have done

well i just called a few junk yards here in THe fabulous state of NY and me being from the south with no emissions testing am now completely frustrated i cant buy cats that are used legally in new york what a f@#$%ing joke so if anyone wants to part with there take off cats and y pipe please let me know the price i will pay shipping

its federal law you cannot buy any used emission parts. But Im sure someone has their old ones. I sold mine to the recycler a long time ago

Yeah, that's not a NY thing, I live in Georgia (well Florida part-time too) and we have no emission testing and you cannot "legally" buy used emission components here either...

Well i just found out i am exempt from emissions because my vehicle is over 8501 gvwr the same reason they made me get commercial plates so screw the cats ill take both of them off and buy a tuner to clear the cel thanks for the help guys

There ya' go...