05 LGT - Power Loss/Stuttering

So i have been chasing a power loss issue for the past 6 months and i really need some advice/help.

 

I had my turbo blow out about a year ago due to a clogged banjo bolt. I replaced the turbo with a factory VF40 turbo and the banjo bolt(taking out the stupid filter). A few months down the line i started to get substantial power loss and stuttering when im about half way throttling the gas and starting at 2.7k rpm to about 4.5k rpm. Ive replaced these parts trying to figure out what it is so far: all spark plugs(NGK), all coil packs, turbo inlet(there was a tiny crack). I have reset the ecu multiple times and have gotten 0 codes. Another thing i have noticed is that when it starts stuttering really bad my access port will start to freak out and show a blank screen while flickering.

 

I am a little confused as to why there are some days where it runs and drives good for a little bit, then start stuttering again and others where its stuttering all the time. I have taken my car to multiple "Subaru" specialized shops and the things they suggested to me have not fixed the issue. Any help/guidance would be much appreciated. Thanks!

As you probably already know and as you'll hear all day long on this forum, the blown turbo VERY often takes out the engine with its debris. At first read, I figured that was where this was going, and I still think a compression test would be a really good idea.

 

However, the flickering AP when you get stuttering actually sounds like good news to me - sounds like you have an electrical problem rather than a mechanical one. I would start by checking all of the main electrical connections - make sure your 3 main engine grounds are not corroded or frayed, make sure your battery connections are solid and not corroded. Then I'd move on to the ECU connections and the ECU grounds.

 

In the interest of sparking other ideas, can you provide details on the car? Miles, miles on the engine, miles on the turbo, stage 1 or 2?

 

When you replaced the turbo and de-filtered the banjo bolt, did you take care of the up-pipe as well?

As you probably already know and as you'll hear all day long on this forum, the blown turbo VERY often takes out the engine with its debris. At first read, I figured that was where this was going, and I still think a compression test would be a really good idea.

 

However, the flickering AP when you get stuttering actually sounds like good news to me - sounds like you have an electrical problem rather than a mechanical one. I would start by checking all of the main electrical connections - make sure your 3 main engine grounds are not corroded or frayed, make sure your battery connections are solid and not corroded. Then I'd move on to the ECU connections and the ECU grounds.

 

In the interest of sparking other ideas, can you provide details on the car? Miles, miles on the engine, miles on the turbo, stage 1 or 2?

 

When you replaced the turbo and de-filtered the banjo bolt, did you take care of the up-pipe as well?

 

Thanks for your response and that sounds like better news than i was thinking lol. Ive got about 147k miles on the engine, around 10k on the turbo, and i am catless up/dp stg2.

As you probably already know and as you'll hear all day long on this forum, the blown turbo VERY often takes out the engine with its debris. At first read, I figured that was where this was going, and I still think a compression test would be a really good idea.

 

However, the flickering AP when you get stuttering actually sounds like good news to me - sounds like you have an electrical problem rather than a mechanical one. I would start by checking all of the main electrical connections - make sure your 3 main engine grounds are not corroded or frayed, make sure your battery connections are solid and not corroded. Then I'd move on to the ECU connections and the ECU grounds.

 

In the interest of sparking other ideas, can you provide details on the car? Miles, miles on the engine, miles on the turbo, stage 1 or 2?

 

When you replaced the turbo and de-filtered the banjo bolt, did you take care of the up-pipe as well?

 

So where exactly are the engine grounds on this car? Going to check it out this weekend.

Two go from the bottom of the cylinder heads to the frame rails. Readily visible once you remove the engine splash guard. The passenger side one may be attached to the exhaust manifold heat shield near the upper O2 sensor, rather than to the head. The third ground goes from the top of the tranny to the frame bracket where the pitch stopper attaches. That one is much less prone to corrosion than the others.

Two go from the bottom of the cylinder heads to the frame rails. Readily visible once you remove the engine splash guard. The passenger side one may be attached to the exhaust manifold heat shield near the upper O2 sensor, rather than to the head. The third ground goes from the top of the tranny to the frame bracket where the pitch stopper attaches. That one is much less prone to corrosion than the others.

 

Alright awesome i will check those spots. Thanks Again!