Engine Rough Idle

MustangGT559

Member

Aug 26, 2015

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Nov 17, 2015

#1

• Nov 17, 2015

• #1

Hello, how's it going. So I have an idle problem. So every time I start my car up (cold start) it idles fine. But when I drive it around, and park the car somewhere and start her up again it starts fine, but it drops RPMs like crazy! Its goes from 1000 to 300ish really quick. But then it goes to 500-600. It sounds likes it going go die and shut down but it doesnt. It runs really good. I recently changed the plugs, spark plugs and cap. And I cleaned out the MAF sensors and it still the same.

 

stykthyn

I want to measure mine. It doesn't look that tall.

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Nov 17, 2015

#2

• Nov 17, 2015

• #2

Dump the codes. A hot surging idle is an issue.

 

MustangGT559

Member

Aug 26, 2015

51

1

8

Nov 17, 2015

#3

• Nov 17, 2015

• #3

stykthyn said:

Dump the codes. A hot surging idle is an issue.

Click to expand...

It gave me code 34 and 10

 

MustangGT559

Member

Aug 26, 2015

51

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Nov 17, 2015

#4

• Nov 17, 2015

• #4

stykthyn said:

Dump the codes. A hot surging idle is an issue.

Click to expand...

And 91

 

stykthyn

I want to measure mine. It doesn't look that tall.

15 Year Member

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Nov 17, 2015

#5

• Nov 17, 2015

• #5

34 egr not opening, egr insufficient flow
91 o2 sensor voltage low, system alwayslean

 

MustangGT559

Member

Aug 26, 2015

51

1

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Nov 17, 2015

#6

• Nov 17, 2015

• #6

stykthyn said:

34 egr not opening, egr insufficient flow
91 o2 sensor voltage low, system alwayslean

Click to expand...

Thank you! You know any fixes for those? I don't have any o2 sensors

 

stykthyn

I want to measure mine. It doesn't look that tall.

15 Year Member

Jul 6, 2006

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Nov 17, 2015

#7

• Nov 17, 2015

• #7

Was your car tuned to remove them? Odds are you do have them down there.

 

MustangGT559

Member

Aug 26, 2015

51

1

8

Nov 17, 2015

#8

• Nov 17, 2015

• #8

stykthyn said:

Was your car tuned to remove them? Odds are you do have them down there.

Click to expand...

I don't think so. Not that I know of

 

stykthyn

I want to measure mine. It doesn't look that tall.

15 Year Member

Jul 6, 2006

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Nov 17, 2015

#9

• Nov 17, 2015

• #9

Crawl under the car in the morning and take a look. They should.be in your h pipe.

 

MustangGT559

Member

Aug 26, 2015

51

1

8

Nov 17, 2015

#10

• Nov 17, 2015

• #10

stykthyn said:

Crawl under the car in the morning and take a look. They should.be in your h pipe.

Click to expand...

I know my car, and it doesn't have the o2 sensors.

 

stykthyn

I want to measure mine. It doesn't look that tall.

15 Year Member

Jul 6, 2006

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Nov 17, 2015

#11

• Nov 17, 2015

• #11

Then you need to check your ecm and look for a chip otherwise you're never leaving limp mode.

 

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jrichker

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Nov 23, 2015

#12

• Nov 23, 2015

• #12

stykthyn said:

Then you need to check your ecm and look for a chip otherwise you're never leaving limp mode.

Click to expand...

Good Advice, take it. Without O2 sensors, the computer has no way to tell is the air/fuel mixture is rich or lean. That's a big invitation for trouble.