When I first start my car and start moving, the car is real responsive and a whole lot quicker. Now when the car is fully warmed up, the car is less responsive and sluggish at times, esp up hills. I have done the following to the car:
-new fuel injectors
-fuel filter
-spark plugs
-plug wires
-distributor
-new vacuum lines
-cleaned intake manifold plenum and ports
-ran fuel system cleaner through
-installed new EGR valve

Can anyone please help? I am thinking its a fuel pressure regulator.

 

Methinks it's a sensor that is only used in closed loop mode.

 

Sounds like the exact same symptoms I had when my knock sensor was bad. I heard it's easier to change on a VG.

 

1) Clean your red coolant temp sensor connector
2) If your 02 sensor is the original, consider replacing it.
3) KS could very well be it also.

 

I thought VG's were always slow ?!?

 

I just got an opinion from a Nissan tech at my friend's work. he saw what I replaced which is a big list, and I did clean the MAF sensor as well. He thinks its the catalytic convter, in which it is the original one. It makes sense to me, so I need to find the best price on one. Can anyone help me?

 

i read this thread just to see if a ve jock got a hold of it lol

 

Muffler shop. $100 installed.
unless you want to go hi-flow.

 

I got a magnaflow high-flow cat for my VE and it bolts right up, flanges ARE included. It was like $80 shipped, but that was with a group deal.

 

the nissan tech didnt diagnose the problem very well because if it were your cat your car would be slow all the time not just after it warmed up. more than likly its one of the sensors people have been mentioning

 

DING!!!!!!!!!!!!!

Consider this:
1) Your "mechanics" (I use this term loosely) seems to replace all the EXPENSIVE parts first. I wonder why?
2) We as owners, replace the CHEAP parts first and work our way up to the expensive parts. I wonder why?

As a collective, this 3-gen section is probably better than 90% of all "mechanics" out there. I strongly suggest you start with our suggestions first. Because if it's something small/free/cheap, you will find out sooner rather than later. What if it's something that only costs $40? What does that mean for the other $500 you just spent on stuff you didn't need?? Your mechanic gonna reinburse you?? I highly doubt it.

Good luck.