Hey there everyone, I just had my Berk HFC's installed this past weekend, and let me tel you you do notice a big difference in power at take off. But there is one problem. now when I am cruising in the city or on the freeway and I step on the gas when the engine in revving around 2800-3000 rpm it feel like the engine is getting no gas and feels like it's going to bog down then all of a sudden it kicks in and starts to accelerate. I did the disconnecting the negative battery cable thing but that did not seem to help. i don't have a CEL on so I am not sure if it's one of the o2 sensors or not. Please help?

 

I have the same problem, although I have stillen HFCs. I got a tune from S&R performance here in Tampa, and got Uprev for the HR motor reflashed. since I reflashed it does not do that anymore. Plus I gained 13 whp from baseline and all options installed.

I would guess you are running super rich as my AFR was at 11 I think before the tune.

The HFC actually blew out my bank 1 O2 sensor. Working with Infiniti now on replacing it under warranty.

Good luck.

 

counds like your 02's youll be getting a ses light soon.

 

Is this common if you get HFC's without changing the ECU mapping?

 

Hmm. just got my FI HFC's installed last week, and drove it around for a tottal of about 100mi, and so far so good, not hesitation at all so far! I only had that hesitation, when my 02 sensor in the header was damaged upon the install. after they changed it, pretty much all gone! runs like normal! SO make sure u have no exhaust leaks at all. Don't know what else too say. and if you have no CEL showing, then the sensors should all be working!?? Keep us updated! but i know the 350Z guy's alot of them have this same problem! so u are not alone bro!

 

I've had mine on know for almost 1.5k miles and it's great!!

 

So which do you guys think it is, the engine is running too rich, exhaust leak, or a bad o2 sensor which there is no CEL on.

 

hmmm..i want some berk HFC's, but this problem and its frequentness is steering me away from them.

 

I got my HFC's & Exhaust from FI about 1 year ago. FI is great to work with by the way! Had them on the car for about 1 month and took them off for that exact reason (left the exhaust on). I had really bad hesitation and "stuttering". At the time there was no ECU update/mapping available. Once I took the HFC's off, the car went back to normal.
Wouldn't think exhaust leak if the shop is reputable (I took the HFC's off myself and put the old cats back on). I had my buddy (SM at the dealership here) check for leaks, and it is fine.
IMO it should be fine if you get the ECU update.

Good luck, let us know how it turns out.

 

MMM Sounds like what my car was doing.. I had to go back to stock. I had no CEL either. Car drove finr till i got on it then it was poop..

 

$hit sounds like I might need to map it after all , I don't have them installed yet but they're on the way...

 

So it seems like what some of you guys are saying is that when i get the Uprev Ecu remapping it'll take care of this?

 

Mine is fine, I just get a weird sound when i let the Rev drop down to around 2k and when i reved hard around 4 k. But then I just got a X pipe in and now it's gone, mostly. None on acceleration and i weird noise very specifically when i'm parked and jab at the throttle and let it fall as the needle hits 2.7k the noise it there for like 1 sec.