I heard about these on my350z.com and was very hesitant to spend the money for another set of Cats. But I got rid of the raspy sound for good! Much better sounding all the way through the rpm range. They seem to be a little more restrictive so I may of lost a slight amount of high rpm hp but I can still chirp in 3rd gear. It's worth the very slight hp loss (if any) for the much improved sound. If you're sick of the crappy sound you're getting from the RTs then consider switching. Thanks Adam at Z1 Perfomance!

Now the problem!! I picked up my car from my dealer on Friday night and drove it home on the highway for an hour or so, enjoying my new, more mature sounding exhaust. When I finally made into town and noticed a strange new vibration at lower speeds coming from somewhere underneath the engine compartment. I could feel the vibration when especially accelerating in first and second gear but once I got going it stopped. The strong vibration even comes through the gas pedal and interior. The engine also stumbles and hesitates at idle. I never had these symptoms before the switch with my RTs. Did my Infiniti dealer not installed them properly? If it's just the Cats causing the vibration, then why the engine symptoms? I'll call them early in the morning but I was wondering if anyone would have any ideas what it could be. I'm freaking out a little and don't want to do serious damage just driving it an hour to the dealer.

Thanks in advance for any response.


G35C 6MT/Dynashield/Z-Tube/JWT Pop-Charger/Nismo Exhaust/Ultimate Cats/UR Pulley & Tein H-Tech Springs

 

It's probably the heat shield of the cat rubbing on your underbody, or the cat rubbing the car heat shield.

If you have any air leaks you'll experience a stumbling idle. Is your check engine light ever coming on?

2004.5 Coupe/5AT/Ivory/Everything but front spoiler/Nismo CAI/Crawford V5/Crawford Cats

 

Ok, I'll have that checked out. No engine lights. Thanks Catafish.

G35C 6MT/Dynashield/Z-Tube/JWT Pop-Charger/Nismo Exhaust/Ultimate Cats/UR Pulley & Tein H-Tech Springs

 

Rubb-a-dubb-dubb...

The gut-o-meter is going off the richter!!!

Quick batman, bend that heat shield or add washers!!!

<font color=blue>The above statements are only my take on the issue. If you disagree with anything I typed then you are 100% right!</font color=blue>

 

I get the picture Neff :-)

G35C 6MT/Dynashield/Z-Tube/JWT Pop-Charger/Nismo Exhaust/Ultimate Cats/UR Pulley & Tein H-Tech Springs

 

Yeah, sound like a rubbing heat shield problem. And your Infiniti dealer actually installed the High Flow cats without a problem? I see your in Ohio so I guess the rules are more laxed over there. Because over here in California it is only legal to replace a stock cat if the stock cat is malfunctioning or damaged. And it is only legal to replace it with another stock cat. Makes installing high flows or test pipes difficult over here if you don't want to do it yourself.

04' G35S 6MT Ivory Pearl, Willow, Premium
Z-Tube / NFC Y-Pipe / Custom Mid-Pipe / 350 EVO Rear Sway

 

Actually my dealer is in Michigan. They had no issue installing.

G35C 6MT/Dynashield/Z-Tube/JWT Pop-Charger/Nismo Exhaust/Ultimate Cats/UR Pulley & Tein H-Tech Springs