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Pete, Technician
Category: Car
Satisfied Customers: 28811
Experience:  17 years automotive training and experience.
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Saab 2003 vector 93 2.0T: I have a 2003 saab 93 vector. 2.0T.

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I have a 2003 saab 93 vector. 2.0T. when you run it for about 20 minutes an get to a stop sign. it is real slow to about 30 mph. an then runs fine. when it does this. you can shut it off for 5 min. an start back up an take off an its ok. code showed po411. the secondary air injection pump. changed it an mass air flow sensor. still does it. what you think?
My name is XXXXX XXXXX I am a professional here at Just Answer. I noticed that your question was not getting a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.

The first thing I would have tested here is to see if there is excessive back pressure from the exhaust system.Usually you would notice this a problem if this was the case all of the time but to be safe it should be checked as I have seen excessive back pressure from a restricted catalytic converter cause the secondary air injection code fault as well as the power loss.

This test is done with a back pressure tester.The back pressure shouldn't exceed 1.5 psi at all engine rpm ranges.If it does I suspect the catalytic converter is at fault needing replaced here.

If this has been tested and found to be o.k. let me know and we can continue if needed.

Thanks Pete
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Customer: replied 4 years ago.

will this cause the car to be slugguish at take off and then come up to speed after the 20 mph mark or 30. cause this is what its doing. an you can shut it off for 5 min. an its ok till warm up again. thanks randell.

It is possible as pressure builds up in the exhaust system with acceleration it may push its way through and allow some acceleration like this here.Shutting it off and turning back on will allow the exhaust back pressure to release out through the exhaust or intake as well..

I am following up with you to see if you still needed help with your question you had asked.If my help didn't satisfy your question please let me know so we can continue.

Thanks Pete