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Discussion Starter · #1 · (Edited)
Just to give a brief situation to what has been an ongoing nightmare...

I purchased the car pre-owned. A lesson which I'm learning the hard way day by day. Apparently, the previous owner had some mods done to it such as CAI, BOV, catless DP w/ wastegate divorce and possibly a boost controller. The car had a stock exhaust with the catalytic replaced with a welded straight pipe.

The day I drove the car off the lot, it was boosting 10psi. My buddy brought to my attention the fact that the car was sold w/o cats and other things were done to it. The previous owner replaced these parts with the stock components minus the exhaust, which he left alone. He also told me that this car was not boosting to the stock level of 15psi.

After the dealer got the exhaust replaced to a stock one, I got them to install the SPT performance upgrade (Intake/cat-back) for the troubles.

I found out there were about 4-6 vacuum hoses missing from the boost control module to the turbo and the intake. That explained why I was not boosting right. When I had the stock exhaust put back in, I was boosting 7-8psi. Well I got those replaced with new ones and the car is now boosting 14.9psi.

Here is my dilema. The car seems moody. When the A/C is on, the car just drags. I can hear the engine fine and the turbo spool louder when I go WOT, but I feel a numbness sensation. The same is happening with the A/C off from time to time. One moment, the car pulls hard. Then it goes back to a weak sensation. Its just aggravating! I feel as if I was in a dream yelling and running, but I cant hear myself and I'm not going anywhere! Also, when the car is pulling hard, I feel a pulsating sensation instead of a smooth linear upward power acceleration.

Picture this... If you are in a air conditioned building, you are breathing nice cool air. You tend to inhale and exhale easier. Now walk out of the building after it rains and the sun comes out right after. The humidity is so high and the air is so muggy that you basically loose your breath. You find it harder to inhale. Its an unconfortable feeling.

That's how my car feels when I go WOT.

The car is going to the dealership on Friday, but I'm worried this problem will still show its ugly face.

What do you guys think it could be? I want to be informed about this situation since I'm new to this car.

Thank you for your time and understanding.

BTW... I did try searching for these issues, but I couldnt find what I was looking for.
 

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well there could be a variety of problems, I think you really should take the BOV off, since they are bad for our cars, and make the car run rich in between shifts, this could be your problem, also, not really clear on what the exhaust is, but if there is not enough back pressure you can have issues as well
 

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Sounds like it may be pulling timing or something. :notsure: Are you sure it's not something simple like a dirty airfilter just not letting the engine breath?
 

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also, no engine management could be an issue, since you have a downpipe EM is a must for a well, safe, running car
 

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Pitcherman said:
Just a thought but if it's been runnig real rich it could need new plugs as well....they could be fouling or on their way out

+1! Definately check and replace your plugs!
 

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SteelDragonSTi said:
<snip>

After the dealer got the exhaust replaced to a stock one, I got them to install the SPT performance upgrade (Intake/cat-back) for the troubles.
<snip>
Here is my dilema. The car seems moody. When the A/C is on, the car just drags. I can hear the engine fine and the turbo spool louder when I go WOT, but I feel a numbness sensation. The same is happening with the A/C off from time to time. One moment, the car pulls hard. Then it goes back to a weak sensation. Its just aggravating! I feel as if I was in a dream yelling and running, but I cant hear myself and I'm not going anywhere! Also, when the car is pulling hard, I feel a pulsating sensation instead of a smooth linear upward power acceleration.
<snip>
The humidity is so high and the air is so muggy that you basically loose your breath. You find it harder to inhale. Its an unconfortable feeling.
<snip>
With the SPT intake, especially if it does not have the heat shield, when you have the A/C on the radiator fans are blowing 160 degree air right into your intake. This is much like you describe for a human when it is hot out and very humid it is more difficult to breathe. The Intake temps that high mean less oxygen for your motor, and also the ECU pulls timing which further reduces power. Add the extra drag on the motor from running the A/C and you are probably looking at about a 30-40HP difference, and that is very noticable.
The same would hold true even with the A/C off, if you are sitting for a period of time the intake temps will go up just from the radiant heat in the engine compartment and have the same effect.

At a minimum you should make sure you have the SPT intake heat shield, and if you can futher baffle/isolate the intake from the radiant and radiator heat in the engine compartment you will be much better off.
 

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Discussion Starter · #9 · (Edited)
Thank you guys for your input. I probably didnt explain myself well enough. Let me clarify some points.

I have the stock BPV in since I bought it. I implied that the previous owner might had one installed since I noticed the bolts were scratched.

I have the stock downpipe mated to the SPT cat-back exhaust. This part along with the SPT intake were installed by the local subaru dealer.

My SPT intake does have a heat shield. The air filter is new and clean. I did notice components of the stock intake still lingering on the fender well. (The box infront of the passanger side front tire)

I do not have a boost controller. I was missing the vacuum lines. It was possible that the previous owner removed his boost controller along with the hoses.

I will consider the plug theory when I get to the dealer. However, wouldnt a fouled plug spit out a CEL for missfire on the cylinder?

I do not have a CEL on the car right now.

Now that you have more clear answers, maybe that will help pin point my problem.

Thank you all for your time. :)
 

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I feel your pain...

I lost over $3000 in returning a used 2005 STI to a bum dealer within a 30 day timeframe (including lawers fees). Totally new to STI's, I didn't see obvious stuff like missing I/C supports, no turbo heatshield, cut front end from a FMIC install and the little blinking black CEL box. Turns out it had a 6 puck clutch, bigger injectors and the dealer just laughed and said SOA would turn down every drivetrain warranty repair.

Anyway - to your performance issues - the intake will rob you of hp during high heat and humidity. I know, I have one. Look for Nhlur's threads here among others on how to rig up a home-made dryer hose ram air. It will also get rid of the fenderwell snorkle/silencer piece.

Unless you go WOT, A/C will cycle on and off and cause some loss of hp also. Replacement of the downpipe (no cats) should really be addressed by an EM (Ecutek or Cobb) which will give you more power and address low boost issues. Dump the BOV and put the stock BPV back on. You'll still hear the fun sounds because of the SPT intake.
 

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I would seriously think of getting EM now! You have no idea what was done to that car and what map is currently loaded. At least with some tuning you will know how the car is tuned and most likely see a ton of improvement. If there were that many vac hoses left off, I would go over that car with a fine tooth comb!
 

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2fas4u said:
I would seriously think of getting EM now! You have no idea what was done to that car and what map is currently loaded. At least with some tuning you will know how the car is tuned and most likely see a ton of improvement. If there were that many vac hoses left off, I would go over that car with a fine tooth comb!
what he said!^^^^
 

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Since the dealership did lot of the work, to return the car back to stock, I would ask them for a ECU re-flash. At least then, you would know that you have the proper EM.
 

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SteelDragonSTi said:
Thank you guys for your input. I probably didnt explain myself well enough. Let me clarify some points.

I have the stock BPV in since I bought it. I implied that the previous owner might had one installed since I noticed the bolts were scratched.

I have the stock downpipe mated to the SPT cat-back exhaust. This part along with the SPT intake were installed by the local subaru dealer.

My SPT intake does have a heat shield. The air filter is new and clean. I did notice components of the stock intake still lingering on the fender well. (The box infront of the passanger side front tire)

I do not have a boost controller. I was missing the vacuum lines. It was possible that the previous owner removed his boost controller along with the hoses.

I will consider the plug theory when I get to the dealer. However, wouldnt a fouled plug spit out a CEL for missfire on the cylinder?

I do not have a CEL on the car right now.

Now that you have more clear answers, maybe that will help pin point my problem.

Thank you all for your time. :)
So your car drives fine and when you go into boost it bogs correct? It could be that your stock cat is broken and particles are floating around. This will cause back pressure when you are WOT but it could still flow enough when you are not boosting so it'll drive normal until you go WOT. It didn't happen to my Subie but I had it happen to another car as it was too low and the cat hit on ramps etc.

Check your cat and see if you can hear rattling. If the stock downpipe was dropped during shipping etc. it could very well be broken.
 

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In regards to the AC...if it is running doesn't the system disable the AC at WOT?
 

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Phoenix45 said:
Since the dealership did lot of the work, to return the car back to stock, I would ask them for a ECU re-flash. At least then, you would know that you have the proper EM.
+1 I didn't think to mention that the stock ECU might not have a "stock" map....that could be your problem.
 

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Discussion Starter · #17 ·
Very valid points.

The dealer believes it could be a vacuum leak somewhere. I will have them check the ECU. I pray to God that this ECU was not tamperred with. If that's the case, I will have a hard time getting them to cover the re-flash. In any case, if this happens to be the situation, I will pursue the dealership were I bought it from to cover the costs.

I'm also considering a protune on and get it over with.

Thank you all for your input. Please feel free to continue the discussion.

Armando
 

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Why would it be hard to get them to cover it....they sold you the car like that and they know the condition it was in. I would settle until everylast little thing was fixed.
 

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If it is indeed flasshed with an AP, why would a map be on the ECU if the guy didnt include the AP with the car? Wouldn't he have to un-marry it from the car (ie returning it back to stock mode) in order for him to sell it himself??

That's my question...
 

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GSRREP said:
If it is indeed flasshed with an AP, why would a map be on the ECU if the guy didnt include the AP with the car? Wouldn't he have to un-marry it from the car (ie returning it back to stock mode) in order for him to sell it himself??

That's my question...
mabye it was ecuteked with other parts on it and then those parts were removed for the sale?
 
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