556 Code for GT

[95&03GT]

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]

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]

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

 

[The Green GT]

Oh. Well thats probably something else then.

 

[mo_dingo]

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]

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.