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Pete, Pontiac Technician
Category: Pontiac
Satisfied Customers: 29096
Experience:  17 Years Pontiac Technician and training.
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2002 pontiac gt engine cuts out at about 40 mph and will

Customer Question

2002 pontiac gt engine cuts out at about 40 mph and will stall at a stop sign if not kept running. engine seems to loose power.
JA: How many miles are on the car? Is it an automatic or a manual transmission?
Customer: 165000 automatic
JA: Are you fixing your GT yourself? What have you tried so far?
Customer: yes, checked sensors,cleaned the throttlebody,cleaned air filter and oiled
JA: Anything else you want the mechanic to know before I connect you?
Customer: it started about a week ago. 9-4-17
Submitted: 1 month ago.
Category: Pontiac
Expert:  Pete replied 1 month 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.

When you say it cuts out at 40 mph is it misfiring or shutting down?

Have you had the fault codes checked/read out at all to see what codes are set with this issue here?

Let me know,thanks Pete

Customer: replied 1 month ago.
it misfires and looses power, at a stop sign you have to put in neutral and keep it running. sometimes after it stalls you have to waite a few minutes to restart.
Expert:  Pete replied 1 month ago.

Is or has the check engine light come on or started to flash at all with this issue and have you had the fault codes checked at all?

Customer: replied 1 month ago.
have not had fault codes checked and engine light is and has been on for some time
Expert:  Pete replied 1 month ago.

O.k.,the first thing that needs done here is to have the fault codes read out to see what codes are set.This can be done for free usually at a local parts store.If you can get the codes read out and post the code info here this will help with this fault.

I have seen the crank sensor cause this type of issue with the misfire and stall out at low rpm and no start until it sits a few minutes.I have had to replace this sensor several times before.I have also seen issues with the throttle body bore being dirty needing cleaned.You might take a shop rag and spray it down with carburetor or brake cleaner and wipe out the throttle bore to see if this resolves the fault.But if you can get the fault code info to me here on this post this will help.Even if the light has been on for some time you may have new codes set for this issue that is occuring now.

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 ( should be a link to click on here or above).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