Ok, read all 16 pages! now I just got my FI HFC's installed by my Infiniti dealer today! so I went to pick up my G, and driving home i steped on the throttle like 50-60% and got this bucking hesitation also! first thing came to my head was this thread!

But on a side note, I have the CEL light beacuse the dealer damaged an 02 sensor on the header. that like one of the main sensors for fuel etc... the sensors on the cats are mostly for emissions and won't cause drivablity issuses! So I'm getting my sensor repalced under Warranty! thank god!

But i am hoping this bad sensor is whats causing my car to have this problem. and it only happens in low RPM like 2000-2500rpm's, and only if i mash the gas. Normal driving it drives fine. After that she revs pretty smoothly no problems. but did not want to full throttle it until i get that new 02 sensor. don't want to damage anything else! my car is a 6MT! I'll be praying next week all is good! LOL.

 

HMM Mike thats exactly what mine was doing but I had no cel.. I really hope it's just the O2 sensor if not then you will have to got back to stock like me.. . Yours being a manual is most likely the sesor I hope..

 

Good luck dude, keep us posted!

 

Well an update!

Dealer replaced my bad 02 sensor in the header. which was dmaged during the HFC install! and on the way home. no CEL, and no more hesitation! hope it stays that way. since i never drove my car in a couple days after the fix! Gong to put my Injen's back on, hope all goes good!

And I tested a rolling start in 1st gear, and man what a diffrence! with VDC off, I got mad wheelspin in first, car never did that before! and hitting 2nd gear, spun tires for a good 3-4ft before it gained traction, it did this before, but not as long as now, and hit 3rd gear, same got a screech pretty good on that shift as well! so i am quite impressed! just hope the Hesitation stays away!! SO we'll see how or if my Injens make a bigger diffrence, i got the stocks on now, took out the Injen's cause did not want the dealer tech's to scratch um up! HAHA. Well just wanted to let you know so far so good! *Crosses Fingers & Toes* !!

 

Great to hear that!!! I have been using the HFC since 2000mi with no ploblems
Maybe by the time that i stalled them the O2 still brand new and easy to take off that is why nothing damage.Have fun on yur G.Right now i got no plan for mine G yet since i just bought a house and wait for closing in next fews week.

 

Glad it worked it I have almost 1 k on my HFCs and they are great so far apart from the noise arrrggg.

Congrates earth0 on the house, is that why we haven't seen you around lately?

 

Good to see you've got the problem fixed. I'm curious, do they need to touch the 02 sensor on the headers to install the HFC's? or did they just damage it by mistake? Because I've heard of a few people getting stuck in the same place when installing HFCs

 

I dont' think you need to touch the O2 sensors on the headers on the install most people were breaking the ones on the cats, i'm sure maybe when they were taking off the stock cats it broke the one on the header.

 

+1000000 There is nothing got to do with Header Sensor.I think they accidently broke it while they are trying to loosen the top bolt.

 

Congrates earth0 on the house, is that why we haven't seen you around lately?[/QUOTE]

Thanks! Bro.and yeh,that's why.So manything i wanna DIY mine new house
before we move in.So im very busy!!

 

^^yup exactly! just that the sensor is so damn sensitive, any kind of Impact on it, or just vibrations from say, trying to use an Impact gun to get the top bolt off. can cause damage to the sensor. so yea my 02 sensor was damaged during the uninstall of the OEM cat, and "Top Bolt"!

 

I see, so I guess I have to warn the mechanic about that part before he does the install. Thanks for the Info

 

Glad to hear it was just the header 02 sensor and not the HFC's.

 

MMM guess what? The issue came back.. My wife has been saying the past week that the car has been acting up ( Shaking while she is driving). So today I started the car for her and it hard started and then was shaking a little bit. When she drove away to go to work I could hear the car sputtering. I called her and she said yes it was shaking again this morning.. Thing is it dosent do it all the time like before. So I called the dealer and gave them a heads up that the issue was back..

 

Oh no, I thought you solved the problem! Tell us whats going on when you find out, could it be bad spark plugs or something clogging the engine?