car studdering at 15 psi Colgged 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]

are you running 15 psi on the stock exhaust, wrotten egg smell usually means time for a cat but then again chrysler says your car will smell like wrotten eggs sometimes, its just the nature of their beast. dsm/chrysler/mopar same diff most parts are interchangle. my friends neon smells like wrotten eggs once in a while when he floors it, the car only had 15000miles, the dealer ship said that was normal, same thing with my friends dakota he only has 10000miles he gets that smell to sometimes idling at a light. if you have a lot of miles maybe you should disconnect the exhaust by the catalyst and look inside with a flash line to see if it is clogged it will look like a screen when you look it in buts its not a screen, check it the same way you look at a window screen when you look at the inlet side of the cat. then you can rule out if the cat is clogged. if the cat isn;t clogged it may just be filtering like shit which really doesn;t matter, the air just won;t be clean coming out.

depending what you mean by dyno tune, do you mean reprogramming the ecu or adjusting an afc.

 

[GstRacer]

well this is what i have done and yes tuned with the afc2 apexi downpipe w/ 3inch high flow cat 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

 

[1fast97gsx]

might be time for a cat ..my car did something similar when the wires went though too. Well .. it didn't really smell that bad but it did what you were saying with the boost going down and then back up and back down ... felt like fuel cut as well. :thumbdown

 

[GstRacer]

well the car backfires a little just like fuel cut and it ahppens fast like pop pop pop pop and the car studders it feels exactly like fuel cut but isn't ive ran this psi plenty beforeno one has ever had a cat that was messed up on the inside?

 

[DSMJim]

Cat's dont generally "clog" up they melt or get burnt up. It sounds to me like your having ignition missfire. I would inspect your plug wires and boots for signs of arking (small pin holes or melted points) and inspect your spark plugs to make sure they are gapped correctly and the proper heat range. I would also look around your coil pack to see if it has any signs of wear or arking or is cracked etc...

If you think it's cloged cat then pull the cat off and try driving around with an open down pipe to see if the problem goes away, but i'm gonna guess that is not it. THe back firing your hearing is the fuel from the cylinders which are missfiring being ignited in the cat and giving that beautiful smell. THe bucking and non acceleration is from the missfire, and the fact that your boost gauge is jumping around is from the fuel igniting at the trailing end of the compression stroke and burning up in the manifold which spools the turbo (sorta like anti lag on a rally car giving the pop pop pop noise).

Hope that helps.