Tommysyko
Full Access Member
March 2022- I received my Whipple 2.9, 4th Gen W175ax with all the bells and whistles, larger heat exchanger, twin 11" Spaal fans, 60 lb injectors, billet dual 68mm throttle body, smaller 3.25 pulley and an SCT X4 tuner for the CA carb legal tune.
Somewhere down the line I have clogged up my stock cats (not too bad considering I have 130K miles on them). Now I'm trying to see what everyone has done in CA to stay carb legal. I know it should be oem cats and call it a day but at $3K for a set from the dealer, I'm worried that they would clog and melt (as the local shop suggests will happen with my setup). Magnaflow has a setup that is carb legal and about the same price but it looks like the Gesi greens are the only thing other than x pipes that will work.
What have you all done? Is there a legit way to make this happen or do I have to just buy OEM pipes and run the Gesi greens when I'm not running the stock ones for smog.
BTW, this all started because I was getting misfires (from what looks like the melted/clogged cats). Idle was fine, driving around town was fine. But at WOT or really at high boost, it would spike higher and I'd get a CEL and misfire code.
I changed out all the plugs, wires and coils and it was still giving me misfires. That's when it was suggested to test the cat. A local shop did a pressure test and showed that I was having clogs in both banks and I was in need of cats. It made sense that at higher boosts, the pressure was too much and had no place to go. Now I need either new cats, new high flow cats or an x pipe solution.
I also want to keep the noise down since this is the family roadtrip vehicle. Headers would be fun but loud as hell and definitely not as easy to swap in and out like the cats and mid pipe sections.
Thanks for the help and feedback.
Somewhere down the line I have clogged up my stock cats (not too bad considering I have 130K miles on them). Now I'm trying to see what everyone has done in CA to stay carb legal. I know it should be oem cats and call it a day but at $3K for a set from the dealer, I'm worried that they would clog and melt (as the local shop suggests will happen with my setup). Magnaflow has a setup that is carb legal and about the same price but it looks like the Gesi greens are the only thing other than x pipes that will work.
What have you all done? Is there a legit way to make this happen or do I have to just buy OEM pipes and run the Gesi greens when I'm not running the stock ones for smog.
BTW, this all started because I was getting misfires (from what looks like the melted/clogged cats). Idle was fine, driving around town was fine. But at WOT or really at high boost, it would spike higher and I'd get a CEL and misfire code.
I changed out all the plugs, wires and coils and it was still giving me misfires. That's when it was suggested to test the cat. A local shop did a pressure test and showed that I was having clogs in both banks and I was in need of cats. It made sense that at higher boosts, the pressure was too much and had no place to go. Now I need either new cats, new high flow cats or an x pipe solution.
I also want to keep the noise down since this is the family roadtrip vehicle. Headers would be fun but loud as hell and definitely not as easy to swap in and out like the cats and mid pipe sections.
Thanks for the help and feedback.
