Running lean code and ride control question

Bacondoggy

Registered User
I have the codes running lean on both banks - I have like 4 o2 sensors lol, but I was curious, would having a free-flowing exhaust (mustang v6 headers, no cats no res) affect the o2 sensors and making them give incorrect parameters?
Also, when I press down for firm ride, (at least on my 89 SC - rip) on the instrument cluster, a green light that says "firm ride" lights up. On my 91, I don't see that. So is their not a light on the 91's or is there possibly something wrong with my arc?
Thanks!
 
I have the codes running lean on both banks - I have like 4 o2 sensors lol, but I was curious, would having a free-flowing exhaust (mustang v6 headers, no cats no res) affect the o2 sensors and making them give incorrect parameters?
Also, when I press down for firm ride, (at least on my 89 SC - rip) on the instrument cluster, a green light that says "firm ride" lights up. On my 91, I don't see that. So is their not a light on the 91's or is there possibly something wrong with my arc?
Thanks!

im not for sure but my 92 has the auto light so... i doubt the 91 didnt but maybe the bulbs burnt out... or ther is somthing wrong with it cuz when you give over 1/2 or somthing the ride control should got to firm and also for hard braking are you sure your car has all the auto ride stuff...
 
every SC had ARC. i think ur bulbs is just burned out which is a pretty easy fix.

opening up your exhaust wont affect how the o2's read. on a 91 SC i believe u have 2 sensors. one on the driver side manifold and one on the pass. side downtube. u should just check to be sure.
 
yes I have 2 and they both have been changed. still the same code. the CEL comes on after driving a few minutes and can vary from staying on steady to flickering randomly on and off while driving.
 
then i would suggest u check for some major vacuum/boost leaks.

u ever hear a wierd sound when u shut the car off ?
 
SWAG
1. O2 sensor wire connection loose, or bad ground. (or bad O2's)
2. Fuel filter
3. Fuel pressure regulator
4. Fuel pump
5. Fuel injectors (perhaps clean with gas additive)
6. Vacumn leak
 
ok - no weird sound when the car is shut off. Checked the fuel pressure at the rail and seemed fine. MAF is cleaned and car instantly dies when I unplug it. the IAC is new (from Ford). I checked for vac leaks by using starting fluid, soapy water and found none. replaced the PCV valve as it was faulty, but did not make a difference. I am confident there is no vac leak in the SC setup, as my father actually made a makeshift device that put a uniform 3/8" "gasket" of copper RTV around all the tubes before i put them back on... looked around for cracked or bad vac lines and they all seem decent...
 
i would try #1,2,and 5 on sail7seas list.

start with fuel filter; its cheap and easy.

try seafoam(avail. @ autozone or advance auto) and dump it in your tank. works for me.
 
I forgot to mention - fuel filter is brand new... I am pretty sure the o2 sensors are connected - I can check the ground - but they are both pretty new. as far as fuel injectors - I did use lucas fuel additive to clean the injectors - and the car only has 70k on it, and the engine - maybe 4-5k is there a way to test the fuel pressure regulator?
 
yea there is, pull the hose off the top of it. if gas comes out of it its bad.

a bad fuel pressure regulator will usually have u running rich tho.

try the seafoam :)
 
right below the return plenum. in the circled area below the plenum. its a little black round thing with a vac. hose comin out the top of it.
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I'll have to check the FPR, but I don't know what seafoam would do - the car has 70k original, and about 4k on the engine itself... I guess it can't hurt... I have heard nothing but good things from it
 
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