Lack of power,backfires when accelerating

2001 TOYOTA 4RUNNER
120,000 MILES • 3.1L • V6 • 2WD • AUTOMATIC
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SETNSTONE
  • MEMBER
  • 1 POST
Car loses power, backfires, bogs down when accelerating from a stop. Have changed; plugs,wires,all coils, MAF sensor. replaced throttle body, new air filter. problem getting worse with time.
Jun 28, 2019 at 8:26 PM
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JACOBANDNICKOLAS
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 110,190 POSTS
Welcome to 2CarPros.

Have you scanned the computer for codes? I would do that first if the check engine light stays on while the engine is running. First, here is a link that explains about backfiring.

https://www.2carpros.com/articles/engine-backfires-while-running

Now, since there is a power loss, my first suspect is low fuel pressure. Here is a link that explains how to test pressure:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Here are the manufacturer's specs for pressure:


Fuel Pressure No Vacuum 38 to 44 psi


Now, if that checks good, next I would check for a plugged catalytic converter. Here are a few links that explain symptoms, how to check one, and in general how they are replaced:

https://www.2carpros.com/articles/bad-catalytic-converter-symptoms

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

https://www.2carpros.com/articles/catalytic-converter-replacement

Let me know if this helps and the results. If you have other questions, let me know.

Take care,
Joe
Jun 28, 2019 at 9:23 PM
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