Poor acceleration, will not go past 4,000 RPM's, no codes

Tiny
STXHAMMER
  • MEMBER
  • 2002 FORD EXPLORER
  • 4.0L
  • V6
  • 4WD
  • AUTOMATIC
  • 160,000 MILES
Sounds like a supercharger when accelerating (may be a vacuum leak just not sure where to start). O2 sensor was replaced, DPFE sensor replaced, serpentine belt replaced. Maybe the ECM went? Just seeing if it’s something to repair myself or just take it to a mechanic and be done with it.
Monday, December 31st, 2018 AT 1:10 AM

7 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Good morning,

It sounds like you have a clogged catalytic converter. it will make that sound and limit the rpm.

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

You can verify by unbolting the front pipe and driving the car and see if it still happens.

https://www.2carpros.com/articles/engine-has-low-power-output

Roy
Was this
answer
helpful?
Yes
No
Monday, December 31st, 2018 AT 6:00 AM
Tiny
STXHAMMER
  • MEMBER
  • 45 POSTS
That was one of my thoughts. Thank you. Do the cleaning techniques work or just replace it? I think when the engine was replaced they didn’t plug the pipe and got oil in there but who knows.
Was this
answer
helpful?
Yes
No
Monday, December 31st, 2018 AT 6:14 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
There is no cleaning to the catalytic converter at all. The issue is it melts internally and creates a blockage.

Go to rockauto. Com and get a walker catalytic converter they have a five year warranty on them.

Roy
Was this
answer
helpful?
Yes
No
Monday, December 31st, 2018 AT 7:04 AM
Tiny
STXHAMMER
  • MEMBER
  • 45 POSTS
Thanks Roy! Just got to figure out which catalytic converter it is. Appreciate the help.
Was this
answer
helpful?
Yes
No
Saturday, January 5th, 2019 AT 11:23 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
The pipe comes with both converters so no need to figure which one.

You are welcome.

Always glad to help.

Roy
Was this
answer
helpful?
Yes
No
Saturday, January 5th, 2019 AT 11:25 AM
Tiny
STXHAMMER
  • MEMBER
  • 45 POSTS
Update: replaced the catalytic converter near bank 2 O2 sensor. And also the passenger exhaust manifold which caused the air leak. The truck is still not going past 4,000 rpm and low power. Maybe MAF?
Was this
answer
helpful?
Yes
No
Sunday, February 24th, 2019 AT 10:26 PM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
No, not at all.

Have you done a compression test to verify the engine can produce power?

https://www.2carpros.com/articles/how-to-test-engine-compression

Roy
Was this
answer
helpful?
Yes
No
Monday, February 25th, 2019 AT 1:37 AM

Please login or register to post a reply.

Sponsored links