[blloyd94]

I have a stock 94 mustang v6 and I have been having a lot of hesitation during take off, acceleration is so minimal that it sould like it is about to die and then all of a sudden it will finally start accelerating correctly. This hessitaton usually accurs for about 2 seconds which is usually when i am about in the middle of the road, which is a major probelm when i am trying to get out of oncoming traffic. I just replaced the motor not to long ago, it has less than 500 miles but this was a problem even before i swapped the engine.
I just replaced the upstream o2 sensors today but not much of a change used a OBD-II code scanner today and got P0174 System too lean (bank 2), I have no clue what my problem is, i thought it was the o2 sensor but that didnt do much. I replaced the engine because i blew a head gasket. Any help would be greatly appreciated, thank all of you

[green4money00]

check for vacuum leaks. change your fuel filter. is that the only code?

[232-K7]

Originally Posted by green4money00

check for vacuum leaks. change your fuel filter. is that the only code?

+1

that definitely sounds like a vacuum leak, also since you have a lean code on only one bank.

[b1lk1]

One very important thing to remember is that just because you get a code does not mean the sensor highlighted by the code is bad.

[Shine1Stang]

how many miles on the car? ya first check for vac leaks, fuel filters are cheap, could possible be stopped up injectors too.

[blloyd94]

There is less than 500 miles on the engine and i only drove my car for less than a year with a new fuel filter. I just checked my vaccume line and im getting about 18-19 inches of vaccume, the book says i should be in the range of 17-22 inches. Is there anyways to test the injectors without replacing them? Thank you all for you help thus far

[blloyd94]

I pulled the codes agian and only the same code came up. There was alot of coolant that ran through my exhaust, could it be that my cats are bad and thats whats causing the problem?

[green4money00]

bad cats wouldnt cause a lean condition code. you can check your injectors a few different ways. you can check the power with noid lights. you can check the resistance of each individual injector with a DVOM. there is a special tool that fires injectors one at a time while you watch a fuel pressure gauge and look for pressure drop. sometimes you can use a mechanics stethescope on each injectors and be able to hear if they are firing or not> if one sounds different it is probably bad

[blloyd94]

Would bad cats be part of my hesitation problem? I know a aftermarket exhaust can give you extra horsepower so i would assume that if its plugged or something it would affect my performance