Ok has happened 2-3 times. When I'm rolling in 1st gear very slow like 5mph if a gun if the car it hesitates something nasty almost like fuel cut. I accually lung foward in my seat. Has anyone had this issue before?? It also takes a good 2-3 seconds to downshift with I go WOT. I know these have a learing ECU and my wife drives it most oif the time and she never floors it I mean never. Could this be the issue. The car is freaking out when I dump it? there is NO CEL..

 

High-flow catalytic converters are very similar to the OEM catalytic converters. They do not cause problems like you describe.

 

could be several things, fouled spark plug, clogged injector, throttle position sensor, etc... but as davidv said, that cats are least likely the issue

 

Interesting.. What year model Z?

I think I may know what you are talking about. I also have Berk HFCs and one time (and only one time) I was going to pass a slow car and when I got to the side, downshifted, gunned it and the car hesitated for a second and then resumed gunned power..

Other people who have test pipes also have reported incidences similar to yours and mine.

But like I said it only happened once to me and it never happens at the racetrack so I really never cared..

 

I'm guessing that the high flow cats leaned out your gas mixture.<O</O
<O</O

Once I put headers on a truck and had this problem. Since it was carbureted, all I had to do was drill out the jets in the carburetor.

<O</OOn a fuel injected engine like the -Z- has, you would need to richen the fuel mixture somehow. Perhaps you need a Utec.

<O</OThe good news is that it would probably give you more horsepower.<O</O<O</O

 

My car is a 08 Z with 1400 miles. AN I have no CEL lights.

 

Your problem is most likely what gsingh350z described above. I have test pipes on my 07 and I get that hesitation between 2 and 3k rpm if I suddenly open the throttle. My 03 did not do this.

 

Make sure u don't have an exhaust leak...

 

reset ecu?

 

+1 100% with davidv

 

I will try this on tomorrow. But I was also told that these cars learn driving habits and a few others have said they had this issue after babying the car
(Cars were stock). I just did my first LOF Saturday at (1250 miles) also had been pretty easy on her. Just started really opening it up. So possiable driving it easy for the last month and a half and only driving in the city the car thinks I drive like Mrs.Dasiy.. So there are a few things I'm gonna try. I'm also just wating for funds to get reflashed..

 

Think you might be experiencing the fuel cut that happens when you hit the rev limiter . It's happened to me several times including this morning . Happened when I was stock to now ( spacer , test pipes , catback) I'm hoping the Technosquare reflash will get rid of it.

 

would a tune help or reseting the ecu?

 

I thought of fuel cut but a 2k RPMS.. If I have fuel cut there then something is wrong. What about the ECU adapting to driving habits??

 

Just installing HFC or TP, there is nothing to do with ECU. Some people installed bigger piping size than berk's hfc, has no issue. You might wanna run to autozone and scan it, even you didn't get the light on. Or i will replace berk hfc to stock one and see.

 

And one more, could you let us know if you have any other mods?

 

I have no other mods, Car is stock just the HFC's. Scanning it is an idea but removing them just to see is not.If I remove them the stay out.. Till I can get flashed at the same time. Which is some time if Jan or Feb..

 

^only wit high flow cat n reflash ecu is waste $ IMO

 

just a thought but could any of the sensors on the cats be bad or got dinged during re-install that would cause problem?

 

If sensor was damage or bad, it will throw light.