So about 2 years ago my car started to act real funny. It wouldn't boost past 5 psi. I tried a few things. Replaced maf, map, and replaced the whole turbo with coolant lines, oil lines and exhaust manifold. Didn't fix the problem. Took it to dealership and they didn't know what was wrong. I kind of gave up after that and just drove it like that. On and off it would work. Usually when I turned it on it drove fine until I hit the high way and put it on cruise control. It really bothered me that I had a sports car that really wasn't very fast, but I couldn't fix it so I learned to live with it. About a week ago something else happened. While driving down the highway, my car marked engine power reduced on the dash board and dropped down in velocity. After that the car was limited to 25 hp. Very slow. It's throwing three codes: p2178, p0087, and p0101. My car is pretty much stock. I was going to do some stuff, but never did because of the issues I've been having. It has some bolt ons: aluminum intercooler and piping and a cold air intake. Other than that its stock. No tune or anything. If anyone knows how I can fix my car, I would greatly appreciate it. I have been wanting to do so much, but I can't seem to get it to even run normal. All help is appreciated! God bless!

 

What intake?

Have you performed a boost leak test?

 

I actually have not. Would a boost cause these kind of issues?

 

If I remember correctly that p0101 is famous for a boost leak and it could be the source why you can't boost past 5psi

 

It would certainly cause the low power issues. I didn't look the other codes up, little to lazy for that tonight

 

I will make a boost leak tester and perform a boost leak test. Any suggestions on how to go about doing a boost leak test?

 

I ran a boost leak test and it was leaking. Took care of the problem, but still says: engine power reduced. Can't even go past 70 on the road. Car is only using about 25 hp. Any ideas as to what it could be?

 

I replaced the fuel pump and that didn't fix the problem. Does anyone know what to do? Has anyone had this problem and fixed it?

 

You usually have to clear the codes to get rid of the eng pwr red. Otherwise is just stays that way.

 

P0087 states fuel rail pressure low. Is this an lnf car, if so which fuel pump did you replace? Test the sensor to make sure thats good as well.

 

P2178 states fuel trim system rich at cruise or accel

This could be caused by the boost leak

 

Yeah you're right. I fixed that. It did have a boost leak but I took care of that already and I've replaced the fuel pump.

 

Well I disconnected the battery after I replaced the fuel pump and when I turned on the car the engine light was off for about 10 seconds and then it came back on.

 

So this car has two fuel pumps? I was unaware of that. I replaced the one in the tank. Where is this sensor located and how would I test it? Also where is the second fuel pump and how would I go about checking it?

 

Hpfp that runs off the cam, you should be able to hear it at idle if you have an lnf motor. Top right side edge of the valve cover.

 

Im not sure where the rail pressure sensor is if an lnf guy can step in

 

Would you happen to know how to check it and or replace it?

 

You have to have a logging tool to determine what fuel pressure it's providing. At idle it should be around 500psi, and iirc the fuel pressure sensor is built into the hpfp so you can't just change it

 

I checked it and I think it was like 32 psi at idle. I assumed that was the hpfp so I removed it to look at it, but I can't tell if it's good or not just by looking at it. Is there anyway to know if it failed or if it's still good?

 

If you checked it with a logging program and it was only 32psi your car would not be running. If you hooked up a pressure gauge to the schrader valve on the fuel rail, that is the low pressure side. Which 32psi is low, the low pressure side should be around 60-70psi iirc

 

Yeah I hooked up a pressure gauge. What would cause the pressure to be so low? Where would I get a logging program to check the high pressure side?

 

Check the throttle body get it cleaned and serviced or just buy a new one amd reprogram it

 

his fuel pump seems to clearly be bad why mess with the throttle body??

 

I thought so too. I'll replace it. Any other thing that would cause this issue? Could the throttle body cause this issue?

 

If you only have 30 psi on the low pressure side you may need to change your fuel filter or something