car studers at 15psi need help Clogged CAT????

[GstRacer]

well i was on the highway and i downshifted to 3rd geaar at like 70mph and the car wouldn't go anywhere and it was backfiring i was running 15psi and it sounded like fuel cut but i had just got the car dyno tuned with 15psi and it ran fine but now when i get around 13 - 15 psi it wont go anywhere and it pops out of the exhaust and the boost guage jumps a couple of psi back then back up quickly. my buddys said it smeels like rotton eggs behind me so is this a sign you think that the cat has to go thanks alot

 

[x camaro owner]

to check the cat you take it off the down pipe look in it with flash light and it should look like you are looking through a screen, i am sure you know what a dirty screen look like.

as for the tuning are you using an electronic boost controller or mechanical. if mechanical baromic pressure changes combined with humidity changes from the day it was tuned will affect your boost and possibly make you hit cut if you were tuned that close to it.

 

[TurBoGs-T]

did you dyno with racegas i've heard rumors of certain racegas causing TEMPORARY problems with the cat.

 

[GstRacer]

no race gas and these are my mods apexi downpipe injen intake nology plugs and wires greddy evo exhaust greddy type S BOV ported 16G turbo and wstegate DSS upper IC pipe dejon tool lower IC pipe rewired 255 fuel pump ported o2 houseing ported evo3 Manifold AFC2