my 02 Corolla (230k miles) has low power, especially uphills. I did a vacuum test and fuel pressure test, as I was suspecting a clogged exhaust or a faulty fuel pump.

Both readings are normal, except that when the electrical fan turns on, the vacuum drops a bit (2-3 mHg, remains within specs) and the fuel pressure fluctuates very rapidly (the needle shakes). Can I make any conclusions based on these observations, or should I be testing something else to understand why I have low power uphills?

Thank you for your help!

  • When was the last time the car was serviced? I'd be checking for a blocked fuel filter long before a blocked fuel pump. Feb 21, 2020 at 13:51

2 Answers 2


Given the high mileage, you should consider a compression test before troubleshooting any further.


Restricted exhaust by plugged cat converter. Test by opening any exhaust connection before the converter ( loud, but only for the test).

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