[mikecsti]

Hey, I need some help with this one. I think I mite have problem with the STI. In 3rd, 4th and 5th I could put my foot to the floor at 4.5K and the stock boost gauge would go right up to .1 bar. Now I know that .1 bar is 14.5psi like the car should be making stock. By the way the car is stock and has 5,900 miles on her. Now it goes up to .08 bars at 4.5k. The highest it will go to is .09 bar line and it will not make that till 5,500 rpm. The other day when I noticed it was just below the .1 bar line. It seems that I'm making less and less boost the more I open the car up. It just started doing this last week. The temp is the same out side, it has not changed. What could be wrong? Is it the stock boost gauge, I did not see anything lose lines in the engine bay. Should I reset the ECU? Any help would help me out.

Thanks

Mike

 

[steelhead]

Take it to the dealer and have them check it out. Take advantage of the warranty while you still have it.

 

[evilSTi7]

Is your throttle position the same everytime your looking? the ecu might be pulling boost back a little because of a bad batch of gas, or whatever. i would say watch it next time you fill up and see if it changes at all.

 

[SubySteve]

When you shut your car off, where does you boost gauge sit on 0 or below it. If it sits below it, you have a messed up gauge.

 

[sizzflair]

^my stock gauge sits a lil below 0 too. I thought it was normal cuz it was how it was from day 1.

 

[evilSTi7]

it should be in negative when your idle because the turbo creates a vaccum.

 

[sizzflair]

^no he's saying when the car is totally shut off

 

[twiSTies]

sounds like such a small difference in measurement that it could just be the gauge itself.

 

[LOLSTi]

sounds like such a small difference in measurement that it could just be the gauge itself.

yep.

and don't forget your car will feel "slower" as time goes on because you are more used to the power.

 

[Max-Q]

I had the same sort of problem with my 2005. I would drive it around at a very normal speed and not use boost most of the time. Then I started to notice when I would floor it the boost would not go up even to .1 bar it seemed to max out at .08 bar. I am guessing the computer got used to the way I drive and it became more conservative too.

I solved the problem by installing the Cobb AP Stage 1 with the 93 oct HWG map. Now I have no problems at all achieving boost. It will almost instantly boost up to .11-.12 bar and hold until about 6,000-6,200 RPM in every gear but 1st.

My new dp and exhaust should arrive today and we'll see how she does with Stage 2.

 

[mikecsti]

I'm going to take it to the dealer tomorrow for an oil change so I'll see what they say about it.

Not bad gas, I filled up the tank two days ago and nother changed.

The boost gauge reads 0 when it's off.

Maybe that's the problem. Every day the car hits .05 bars. I really do not go past it that much. I'll reset the ECU and I'll see if that's it.

The shop got my Cobb AP in last month but I did not take it I spent the money on a new heat exchanger and two tanks for my mustang

Sound good. I want the Cobb AP pro tuned with Cobb DP with cat and Cobb catback. I have to wait the mustang comes first.

Thanks for the help

Mike

 

[vroomadoo]

Reminds me of a post where the guy had the same problem. It turned out he had a clogged catalytic converter. If I remember right it took the service dept three days to figure it out so good luck on that one.

 

[mrida]

Reset the ECU. test and see. Bad gas will make the car pull timing, but i have never seen it modify a wgdc table, soo i dont think its limiting boost. Also just because you refilled doesnt mean automaticaly the car will adjust timing back... the learned knock correction factor is still there, soo the only way to see if thats it is to reset the ECU.... unless you have street tuner.
-- Also stock boost is 1bar, not .1. 1bar is equel to 2 times normal atmospheric preasure or 14.5 pounds per sqaure inch.

 

[mikecsti]

I love the dealer:lol: I told them the problem I was having with it. They asked me what is it so post to be reading They said they tested the gauge and the gauge is fine. I said well Why is it not making max psi, they said they drove the car and it felt fine, no problem at this time:clap:

At least they found his problem.

I'm reseting the ECU tomorrow for max power. I hope that dose it. I hate knock you're right, sorry man.

Mike

 

[ParkerSTi]

When you shut your car off, where does you boost gauge sit on 0 or below it. If it sits below it, you have a messed up gauge.

This is NOT true. The boost sensor was put together in Japan somewhere and at an altitude of 5800' like me it will read below 0 when the engine is off because of the pressure behind the diaphragm at which the unit was assemblied.

Parker

 

[asf]

Reminds me of a post where the guy had the same problem. It turned out he had a clogged catalytic converter. If I remember right it took the service dept three days to figure it out so good luck on that one.

That sounds nuts!

I would be pretty concerned that something would actually pass through the motor and turbo to actually clog the cat. Whatever it was prbably clogged everyhting upstream too...

Unless the guy bashed the cat by running over a log or a massive speedbump or santa's reindeer or something like that.

 

[Latesleeper]

My car stock never hit .1 MPA on the stock boost gauge. I would only hit between .8 and .95 max. Maybe it's the winter gas.

 

[mrida]

Winter gas, summer gas ?!?!?! 93 is 93 brotha, no if and whats about it. Bad gas will cause the car to pull timing, even after the tank is empty the knock correction takes a LONG while to relearn for good reason.... so the motor doenst go KABLEWY. ECU reset will set all the correctrion tables back to zero, if the car still isnt hitting 1 bar after that then the problem is a mechanical one, or a very small vacume leak. Option 2 is pretty unlikely

 

[BigJon]

Hes looking at the stock boost guage and thinking it measures in bar. It doesn't man............It measures in megapascals - - - - - 0.1 megapascal = 14.503 773 801 pound/square inch [absolute] and - - - -0.5 megapascal = 72.518 869 004 pound/square inch [absolute]

There you go.... I too have the same issues with not hitting supposed full stock boost on my 06....and i have 1200 miles on it. It seems to me that boost has fell off slightly since 800 miles. I have tried full pedal at all different gears at all different speeds....to no evail. I alos have done the silencer cutoff removal mod and an axleback TXS muffler. I was told by the local dealer to do an ECU RESET.....then drive the car to full boost in every gear to redline a few times, etc....

To reset the ecu ..... Taken from scoobymods.com...

I use this method quite often. It will take some time for your ECU to relearn the mod, so be patient. Also, your gas mileage may go down. You may want to do this reset after any mods you put on in the future.

QUOTE
Special thanks to RiftsWRX for allowing us to post this mod...

1. Disconnect the negative battery lead.

2. Let the vehicle stand for at least an hour. LONGER if need be. The motor must be cool to the touch.

3. Once cool, reconnect the battery lead, close the hood, and start the vehicle. DO NOT touch the gas at all!

4. When the car has reached operating temperature, or the cooling fan has gone on and off once, shut off the car.

5. Turn the vehicle back on and go for a drive based on what you want the car to do. Want every bit of horse power? Take 1st and 2nd gear to red-line a few times. Want to teach the computer that your just a commuter? Drive nice in some various traffic conditions for about 20 minutes. Then go home and shut the car off.

6. After that? Drive the car like normal, you've paved the way for what you'd like the computer to aggressively try and learn. It will take a few tanks of gas before the computer will be "tweaked" for one manner of driving or another. The first tank may also show a drop in MPG around town, that will go away soon enough.

another person said: to give the ECU some time to learn.
to reset the ECU, disconnet the battery & step on teh brake pedal a few times. then reconnet the battery.

 

[Endless_STi]

Yeah, I am having the same problem with my 05 STi. It have about 6,300 miles on it. I left the car at 3rd gear today and floored it, the stock boost gauge went up to only .09. I think it use to go up to .1 when I first floored it after my 3,500 mile oil change. I don't full throttle my car often because the floors are always wet now-a-days. Also, when I shutoff my car the gauge sits slightly below 0. Do you guys think I should full throttle my car more often and let the ECU relearn itself? Or simply follow the ECU reset options?