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Discussion Starter · #1 · (Edited)
Alrighty, Back at it.

00' 9-3 auto.

New DI in place.

When getting into the throttle there is a hesitation or stutter. When any boost comes on its also there, Not slam you into the wheel. But "jerky".
When the BPC has all the vacum lines it will barely get into the upper green of the stock Boost gauge. If the bottom 2 are disconnected I get the mid yellow boost. If I connect the Just the middle vacum line on the BPC Once again the mid yellow boost.
The top vacum line has been dis-connected and a bolt and zip-tie is used, So I already tried that route as well no differance.
The ruff idle is gone from thread 1...

So lets re-cap- Between this thread and the last.

New DI
NGK Plugs
Vacum Line "R" is off.bolted, and zip tied.
NO Vacum leaks.
Vacum lines around the TB are good and the FPR.
Traced O2's all the wires are fine nothing cut/broken.

Also No engine codes sence the new DI has been installed. SO I have nothing to go by. the CEL is not coming on.

So, Saab Guru's. I leave it in your hands whats my next step?

Thanks once again guys!

EDIT- I wrote BPV I ment to say BPC

I did this little test here-
http://www.saabwiki.info/index.php?title=NG_900/9-3_Boost_Pressure_Control_Valve
 

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Discussion Starter · #3 · (Edited)
So, have you replaced the BPC yet?
EDIT- I ment BPC

I have not tried to replace it.Could that cause the stuttering even if its been bypassed?
According to a thread I read about bypassing it . It would no longer stutter....And give base boost smoothly.

Not by-passed I get in the green for boost with stutter.

By-passed I get base boost But stutter is still there.
 

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Discussion Starter · #4 · (Edited)
Does it sound like a bad C.A.T ?

Has hesitation when stepping on it. Doesnt boost correctly when the BPC is hooked up correctly, And I hear slight popping sounds when Im driving. Its not back fireing, If I let off the gas the popping sound goes away.

But I have no check engine lights, Wouldnt a Bad/clogged/dieing cat do a CEL on T7?
 

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Discussion Starter · #5 ·
Diagnosing: A leak in one of the BPC hoses, a bad BPC solenoid, or a bad electrical connection can cause the same symptoms as a dirty BPC valve.

With no power applied, the BPC valve should be open from C to W, and closed from C to R.

If you disconnect the BPC solenoid or bypass the BPC valve ("C", compressor directly to "W" waste gate), you should get base boost (middle of the yellow on the turbo gauge), and no fuel cut.

If you get no fuel cut with BPC disconnected, it is the valve.
If you get fuel cuts with the solenoid disconnected, bypass it to make sure.
If you get fuel cuts with the BPC bypassed, there is another problem

Im just reading thread's and throwing in what I find.

SO its probably not the BPC

Its another problem. Im not sure if its Fuel cut ( when Im on base boost ) or what its a stuttering as I said. And as I just heard driving some very slight popping,tapping sounds. when driving unless I let off the gas.
 

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Try cleaning the MAF sensor (any if you want, knock out the honeycomb screen), it is the silver thing coming from the airbox. You need a torx t25 bit to take it apart.
 

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A clogged cat could cause that, easy way to check is rap on it with a soft mallet, see if you hear it all rattly and broken inside. Or loosen the 3 bolts holding the downpipe and let the flange come a little off the turbine housing to relieve the backpressure.

Drew
 
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