556 Code for GT

95&03GT

New Member

Apr 20, 2007

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Apr 23, 2007

#1

• Apr 23, 2007

• #1

Hey I bought one of those OBD1 readers and I put it on there and got the code

556- Primary fuel pump circuit failure. What does this mean?

also I got 172 and 176 its about the o2 sensor and there reading lean. is there a way I can adjust this.

also I got 332 EGR not opening all the way or something. anyways I unhooked it from the smog b/c I elim. the smog. but I am going to take the egr off.

 

The Green GT

No 13 year olds are safe around me.

10 Year Member

Jan 8, 2006

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Louisiana

Apr 23, 2007

#2

• Apr 23, 2007

• #2

I used to get the fuel pump code and i though it caused my low RPM miss. So I changed my CCRM and no longer got the code. But I still had the miss. I fixed that with 3.73's in the rear end.

As far as the O2 sensors, if one is reading lean, then its shot (unless the car really is running really lean) and the other one isn't far away. I also got that code and changed my O2 sensors and it was gone.

 

95&03GT

New Member

Apr 20, 2007

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Apr 23, 2007

#3

• Apr 23, 2007

• #3

well ya both say lean but about 2months ago I just changed them.

 

The Green GT

No 13 year olds are safe around me.

10 Year Member

Jan 8, 2006

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Louisiana

Apr 23, 2007

#4

• Apr 23, 2007

• #4

Oh. Well thats probably something else then.

 

mo_dingo

20+ Year Stangneter

Aug 26, 2003

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Tucson, AZ

Apr 23, 2007

#5

• Apr 23, 2007

• #5

I would first do a cylinder balance test. If it passes, then move on to yanking plugs. If it doesn't pass, you know you have a cylinder that isn't firing and which cylinder it is.

Next, yank each spark plug one by one and inspect their condition. If one or all is white, you are running lean on that cylinder. Make sure you do them all, just in case. Also, note which cylinder the bad plugs come from.

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

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Apr 23, 2007

#6

• Apr 23, 2007

• #6

FWIW, you can generate this code if you stall the car out. That's not to say there's not a real issue but it can be something as stupid as that.

Good luck.