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Pete, Buick Technician
Category: Buick
Satisfied Customers: 28261
Experience:  17 years Buick Technician experience and training.
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O5 buick rendvesous will not take the fuel going down hwy.

Customer Question

o5 buick rendvesous will not take the fuel going down hwy.
JA: Has the vehicle turned into a gas hog? And how does it start -- same as usual?
Customer: starts good.
JA: What is the model/year of your Buick?
Customer: 05 rendvous.
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: i am a tech trying to fix it.i have changed fuel pump,fuel filter,mass air flow meter And cleaned injectors.
JA: Anything else you want the mechanic to know before I connect you?
Customer: thats it.
Submitted: 11 months ago.
Category: Buick
Expert:  Pete replied 11 months ago.

Hi my name is ***** ***** I will be happy to assist with this today.In some cases I may need more info to assist better.I apologize for any delay.

Is or has the check engine light come on or have fault codes been checked at all to see what codes are set with this issue here?

Let me know so we can continue,thanks Pete.

Customer: replied 11 months ago.
There are no codes or history codes.
Expert:  Pete replied 11 months ago.

Is it a lack of power you are feeling?

Customer: replied 11 months ago.
when you start off down the road it takes gas good for a moment than it is like it is loosing fuel pressure
Expert:  Pete replied 11 months ago.

O.k.,if you havent done an exhaust back pressure test at all this should be done.I have seen several issues with restricted catalytic converters that will cause this type of fault here needing replaced.

The pre catalytic oxygen sensor is removed and the back pressure tester threaded into the oxygen sensor port.Then the engine is ran at idle to wide open throttle to see if the back pressure exceeds 1.5 psi.If it exceeds 1.5 psi at any rpm this indicates an issue with the catalytic converter needing replaced.

If you have already done this test or if this test is done and no issues are found let me know.

If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service,your 5 star rating is appreciated.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.

Thanks Pete