Hello all

I am looking into my next exhaust mod, a HFC.

I have read good things about both. The ONLY thing that I am concerned about is a CEL...

That is the last thing that I want out of this investment...

Which one would not throw one? I have tried researching, but theres mixed answers.

Thanks

 

Neither will throw a CEL. FI HFC is even less likely thanks to their "J" style O2 bung.

 

Neither is "supposed to" throw a check engine light. Nevertheless, there have been reports on the forum of people getting a CEL with both style of cats. Additionally, I have friends locally that have gotten a CEL with these cats. On my G35 I had Berks and I got a code. I currently have FI RHFC but the car was tuned immediately so I'm not sure if I would've gotten a code. Keep in mind you may have to have the car tuned to put the AFR within spec.

 

By no means the end of the discussion, but some additional info:

I have an Injen CAI, FI RHFC, FI Catback on a '13 X sedan...no tune and no code for six weeks.

Sean

 

Just based on my reading the forum for the past couple of years, I would say the Fast Intentions RHFC is the least likely to give you a CEL. I think I can recall reading about 1 or 2 instances when someone got a code with FI.

As the poster above stated, the extended J-curved O2 Sensor helps a lot.

 

All excellent points about a CEL.

You have to make a distinction. Are the few CELs thrown because of the FI HFCs or are the CELs thrown 'legitimately'? In other words, would they have got CELs with or without the cats? Since the cats went in around the time the CELs were thrown, are people making a spurious correlation?

Also, were the cats and sensors installed properly? What age/mileage are the Gs? What other mods went in at the same time?

An anecdotal report of a CEL isn't much help without the variables held constant. Otherwise it's very much like an opinion.

Sean

 

I think in this context "codes" refer to codes thrown due to a out of spec air fuel ratio. Nevertheless, I do agree with you. For the OP, grab FI cats if you are worried about a code and don't plan on tuning your car.

 

Very pleased with FI R-HFC's. I installed them 5k+ miles ago and no codes. IMO and excellent product and great customer support.

 

Thanks for all the great responses!

It's looking like I will be going with FI.

Just wondering now, is it worth the extra 120 dollars for the RHFC or no. Or is it all preference?

Thanks again

 

According to FI, it's all preference. No impact on performance. My G is ostensibly a family DD, and I didn't want to make the ride unbearably raw, so I got the resonated ones.

Admittedly, after hearing the cats along with the 18" resonated pipes, I would have liked to get one or the other 'un-resonated'. It sounds great but it's not quite feral enough IMO ...

Sean