first question, what is the normal operating range of pressure on an afpr or a normal regulator from idle to WOT I get about 4-5 PSI difference is this normal?

second, I keep getting a code 13 O2 seonsor failure, I have a aftermarket fuel mixture guage, it reads anywhere from normal to high to low any reasons why I may get this code?

thanks in advance

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'87 Monte Carlo SS,with '89 IROC 350,700 trans, blew up 3.73 posi stuck with crappy 2.73's neeed gears! hooker headers, flowmaster 2 1/2" exhaust true dualls, recently installed a set of alum vette heads 58cc, new cam for a paxton, recently installed paxton, OMG need a posi bad. So if anyone knows where a buick GN 8.5" rear is let me know.

 

A.1- Yes, 4-5 psi is a little low, usually around 8-10 is the usual.

A.2- Code 13 is the referance pulse. Everyone of our cars gets that, the computer will display it first always. This is normal, unless your light stays on, then something else is going on.

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Rob
'86 TA 305 TPI
Gutted MAF, Ported Plenum
TB Bypass, Home made Cold Air Intake,
Edelbrock T.E.S.
48psi regulator, (Nickel method)

 

Code 12 is No reference pulses to Electronic Control Module (ECM).

Code 13 is Oxygen sensor signal stays lean during warm engine cruise

As to why I'm not sure. I just changed mine when I got codes and the problem cleared up. But, I was basically running stock then.

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_ ___ _
SMasterson

 

SMasterson, Thanks for the correction.

 

You will get a code 13 if the Oxygen sensor is unplugged or has a broken wire to the ECM.

 

I was thinking it was something like that but was hoping that it wasnt, now comes the fun part of chasing wiring, hopefully if Im lucky just the wire hit the header or something.
I went on a long drive about 10 hours so around 700+ miles first thing this morning about 5 min into the drive it set off the light so Ill start searching the wiring.
thanks guys


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'87 Monte Carlo SS,with '89 IROC 350,700 trans, blew up 3.73 posi stuck with crappy 2.73's neeed gears! hooker headers, flowmaster 2 1/2" exhaust true dualls, recently installed a set of alum vette heads 58cc, new cam for a paxton, recently installed paxton, OMG need a posi bad. So if anyone knows where a buick GN 8.5" rear is let me know.