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Matt, Engineer
Category: Car
Satisfied Customers: 21630
Experience:  Honors degree in Mechanical Engineering, worked 8 years as a Formula 1 engine engineer.
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stalling..o2..hesitation..low fuel/reduced control

Resolved Question:

Recently I have experienced stalling for about 1 o2 seconds. I feel a slight hesitation and 4 or 5 of the warning lights come on, usually: low fuel/reduced power/check transmission and the 2 cruise control lights. All for just about 1-2 seconds. Happens maybe 2 or 3 times within a 10 minute period once or twice a day. Is something about to go bad? It's got 105,000 miles. Check engine light is on about 80% of the time and my mechanic says the tester suggest EGR problems.

Jim Moher
Submitted: 6 years ago.
Category: Car
Expert:  Matt replied 6 years ago.
Hello Jim

If the check engine light is on then this typically means one or more of the sensors has failed or has a faulty connection.

The ECU senses this and may put the car into 'limp home' mode which typically limits the revs and the amount of power available. Usually the car is safe to drive for a short distance as the mode is intended is intended to get you home without incurring any engine damage

The quickest route to repair is to have the car plugged into a diagnostic machine which will read off the fault code stored in the ECU (providing the light is still on at this point) and indicate which sensor has failed or whether the fault is more serious.

You can do a very rough and ready check yourself by unplugging sensors one at a time and seeing if any of them change the driving condition which would indicate the most recently unplugged sensor is the faulty one. This method is not foolproof though and reading a fault code off is the better method.

also check the connections to the EGR valve, if either the vacuum pipe of electrical connection are damaged / corroded then the EGR can be on all time which certainly will hurt performance. Its also possible that its a fault with the EGR valve so its worth removing the valve and cleaning it out with brake cleaner, if it looks particularly clogged then replace it.
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