05 TL with a J35a6 engine installed about a month ago still using IM from my original J32a2 only two check engine codes im getting are P0174 & P0171 things I have done include:

*Visually and physically inspecting all hoses that run from IM after the MAP Sensor
*switched throttle body off J32
*switch egr off J32
*valve adjustment to j32 specs (sure hope they are different and this is my issue) (did one before installing engine and once again after check engine light)

Everything I did was based of info on threads already on this forum so I guess my next step is to check the fuel pressure.

I have noticed that when I have a full tank of gas the light decides to disappear and comes back around half a tank of gas maybe a day later .

I will also note that when doing swap from j32 to j35 I was not able to place the fuel line clamp bracket connection on because it wouldn't close flush and I didn't want to break it since its plastic and left it off. I have a theory that maybe when my j32 engine overheated on me it blew a gasket on my intake manifold but i think it'd be more obvious if that was the issue idk and I double checked and the bottom Im gaskets for j35 & j32 are the same.
I used my bluedriver to try to see whats going on stat wise to read the short & long term fuel trim but can only get the stats of when the CEL came on which apparently was idle at the time.

 

If you're sure that you don't have vacuum leak after the MAP sensor then check the fuel pressure with engine running.
For vacuum leak, plug line going to brake booster and line going to the evap purge valve, as those might create lean condition, and watch if fuel trims react.

You would need to create some kind of adapter as I believe TL doesn't have port for connecting the gauge.

What's the reading of the a/f and oxygen sensors?

 

my blue driver isn't able to tell me a/f which Idk what that acronym is for air/ fuel ratio? and oxygen sensor readings. As far as fuel pressure and vacuum leak testing is that something I can do with 20 bucks or is it time for me to go-to my trusted auto shop?

 

You can disconnect those lines and plug them with your finger. Finger you should already have, you probably would need some pliers for the hose clamps, but those can be bought for ~$10.

Here's thread about purge valve: https://acurazine.com/forums/3g-tl-p...essage-915682/
you want to plug line going from the purge valve to the canister, not the line that goes from intake manifold to the valve (one visible on the photo below [black hose 90* on left] is line from manifold to the valve, so not the right one). Disconnect the electrical connector as well and start the car. If you feel vacuum on that line then valve is bad, as it should be normally closed.



I borrowed picture from that thread and marked the brake booster line. Engine might stall if you disconnect that line, so best would be to plug it with something and then start the car, just make sure whatever you use is sealed and can't be sucked in as that would be bad.
Or again use your finger and have somebody else start the car.

If fuel trims stabilize after any of those steps then you found the problem. At first short term should go negative, and after some more time (no idea, maybe even couple minutes) short and long term should be close to 0%. (+-5% is usually good).

Also some cars don't update fuel trims until system goes to closed loop, which might require couple minutes and engine warmed up, so best to use something else than a finger How long you've been driving with too lean code? If purge valve would be stuck open can most likely would set the code for that as well so there is very small chance it's bad.

For fuel pressure, you would need right size T fitting, some hoses, and a gauge. Guess it would be possible to rent it from autozone.

 

Thanks for all the info, I tried renting a fuel pressure kit from oreilys but dont have the right adapter to test fuel pressure.
Ill see what happens with everything else you mentioned in the next day or so.

Been driving like this for 2-3 weeks

 

Some live screenshots of fuel trim

 

Went a head and tried both methods separately, plugged the brake booster line and the lip it connects to let it run for like 10 mins to no real change so I figured I'd spin it around the block but with the brake booster plugged i and didn't make it far nor did I see much of a change.




Also tried plugging the purge valve with my finger and didn't notice any vacuuming or suction from that hose between the purge valve and canister then I tried just the canister and hose that comes before it to no suction
I did notice that my short trims will drop to 0% when I let off the gas.

Any thing else I can try or is it looking like fuel pressure is my only possibility?

 

If you don't have vacuum leak, and oxygen sensors are fine (unlikely that they all started reading wrong at the same time), then low fuel pressure is my next suspect.

 

Just an update I thought I had a vacuum leak over by my EGR valve through a smoke test done by a mechanic so I changed the gasket on there with no luck and even tried using the old egr off my j32 motor.

I'm not sure what that means also when spraying egr with brake cleaner the short trims go down to normalcy. I've never come across nor heard of a leaking EGR valve my 8 years of driving Acuras.

 

Another update I swapped the fuel pump with a used one from lkq and placed 6 new fuel injectors I got rid of P0171 but p0174 for bank 2 is still present and now I have a -0497 for low evap system purge flow any ideas fellas?

 

Either leak or low purge. Since purge valve is mounted to the upper intake and you need to remove it in order to replace injectors I would start there. Maybe one of the hoses in pinched or has hole? Maybe something is stuck? Maybe you somehow connected the vacuum lines wrong?

Did you replace the gaskets and torqued to spec? I'm guilty of leaving my old intake gaskets, but torque wrench is my buddy when working on my car.

I don't think car should react when spraying the EGR unless brake cleaner gets later sucked into the intake.

 

I didn't replace my intake gasket but I did switch it with my old jseries engine I have out back. Ill go over everything once more

 

I know I am late just wondering if you were able to correct the condition?