that the oil sender unit might be the problem with why my car spits and sputters on startup...and when the car gets warm it runs really rough and the volt meter/rpms drops/fluctuate. He said it might affect the fuel pressure...is there any truth to that?

This was my whole situation if you guys remember....

Ok I just got done doing the intake manifold leak fix...in addition to that I have
New Opti
New O2's
less than year old Battery and 170 amp Alternator
New belt
Cleaned IAC and Throttle Body/MAF
Fuel filter less than year old
Coil less than 8 months old
Plugs/wires about 4k miles

Problem is that I have the same problem ive been having for a LONG time. When I come to a complete stop IN GEAR(Auto) and stay there for about 5+ seconds, the RPMS start to drop, and the voltage gauge sstarts to drop slowly(kinda eratically)...the RPMS go from like 950-1000...all the way down to around 550.

I got a code-44...says Left O2 is running lean. My scanmaster is showing the LB Learn going up to like 160 and fluctuating...also the LP is higher. The LO2 was about 2 months old, so I took it out and put in an older one. Since then the SES light hasnt come on yet, but it still runs crappy. When I first turn on the car it'll sputter and spit some, then it'll warm up and be ok...until it gets to running temp, then SOMETIMES it'll just shake like it wants to come out of the motormounts. My EGR and CAT is removed. Scanmaster is showing my Vacuum is fine...BAR is 30 and MAP is 10 so=20.

 

in the lt1's the oil pressure sendor has nothing to do with the car running. It is a dumb device. You could try it of course and if it fixes it we can start blaming all the running problems on the oil sending unit! One of my cars has a mechanical pressure guage screwed into oil sender port, still runs just fine.
Your mechanic may be putting the touch on you. Cause i bet it pays about an hour to change it. Plus retail for the part.

 

Well the part was spewing out oil, so it needed to be changed. Still runs like crap again...but get this...

Their diagnostic equipment DOESNT WORK ON MY CAR..he said they plug it in and it says NO DATA....but they used my scanmaster and he found that the O2's were off...same thing I noticed ofcourse. But ive replaced the O2's, and then put back in the old ones...and still no change. WTF.

I give up...someone want to trade a TA for a bike?

 

No truth on an LT1 f-body. Some cars use the o/p sensor as a fail safe to cut off the fuel pump (I think 3rd gens might), but not the 4th gen.

The people trying the diagnostics probably don't know that your 95 is OBD-I. I bet they are trying to use an OBD-II scanner, because they see the OBD-II shaped DLC under the dash.

 

Yea I told him that on the phone but im not sure if he heard me...I said "well you know its a 95, so its OBD-1 with a OBD-2 hook up"..and hes like "uh yea"
It was an older guy so im sure he's been around cars for a while...but yea he prolly used OBD-2....I figured they would be able to figure it out, but who knows....

 

Mitchells Online has the oil pressure sender linked to the fuel pump on 95 impalas. I bet its like that on f bodies too. Completely incorrect, but thats likely where your mechanic is getting his info from. Ask him and see...