96 coupe 3.8 with code "P1151"

I have a 96 mustang with 3.8..
After topping off fuel tank, I got check engine light which had error
code P1151 "manufacturer control fuel / air mixture..
I confirmed gas cap was tight, cleared error code with scanner.
Same error code keeps coming back. I've checked for dipstick tight,
oil cap tight, checked for vacuum leak using brake cleaner. EGR is
operational when direct vacuum supplied to diaphragm. I've yet to get
on a lift to check ohms of O2 wiring and sensor.
When checking I/M sensors key on engine running at operating temps,
everything shows "ready" except catalyst.... this is after a 15 minute
interstate drive.
Car runs great...(I've reset 3 times two errors each, in the past 60
miles always same code)
Any educated ideas? The list I get from google is long from this
code.. about all sensors, egr valve, egr valve control computer,
vacuum leak downstream from mass air flow sensor etc..
I've also got to check my Hayns manual, it's all I have besides here
and google..

Here's the list from internet..
http://www.obd-codes.com/trouble_codes/ford/p1151.php

All that follows is what's on that page..

P1151 OBD Trouble Code
Technical DescriptionLack of HO2S-21 Switch, Sensor Indicates Lean

What does that mean?A Heated Exhaust Oxygen (HO2S) sensor indicating
lean at the end of a test is trying to correct for an over-rich
condition. The test fails when the fuel control system no longer
detects switching for a calibrated amount of time.

SymptomsYou will likely not notice any drivability problems.

CausesA code P1151 may mean that one or more of the following has
happened:

Electrical:
Short to VPWR in the harness or HO2S
Water in the harness connector
Open/shorted HO2S circuit
Corrosion or poor mating terminals and wiring
Damaged HO2S
Damaged PCM
Fuel System:
Excessive fuel pressure
Leaking/contaminated fuel injectors
Leaking fuel pressure regulator
Low fuel pressure or running out of fuel
Vapor recovery system
Induction System:
Air leaks after the MAF
Vacuum Leaks
PCV system:
Improperly seated engine oil dipstick
EGR System:
Leaking gasket
Stuck EGR valve
Leaking diaphragm or EVR
Base Engine:
Oil overfill
Cam Timing
Cylinder compression
Exhaust leaks before or near the HO2S(s)
Possible SolutionsSee the above list of causes and go from there.
Sources: MotorCraftService.com

at 29 Dec 2004, Chuck ] wrote in
:

> I have a 96 mustang with 3.8..
> After topping off fuel tank, I got check engine light which had error
> code P1151 "manufacturer control fuel / air mixture..
> I confirmed gas cap was tight, cleared error code with scanner.

Does your gas cap have a leak? This has come up before in the group and
a few times it got solved by replacing the gas cap...



--
_ 1995 Mustang V6 Coupe (Bright Blue)
|_| Member Modern Mustangs of North America (MMNA)
http://mustang.fdns.net
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On Thu, 30 Dec 2004 14:45:35 GMT, Paul > wrote:

>at 29 Dec 2004, Chuck ] wrote in
:
>
>> I have a 96 mustang with 3.8..
>> After topping off fuel tank, I got check engine light which had error
>> code P1151 "manufacturer control fuel / air mixture..
>> I confirmed gas cap was tight, cleared error code with scanner.
>
>Does your gas cap have a leak? This has come up before in the group and
>a few times it got solved by replacing the gas cap...
Pretty sure the cap is fine...
In checking the "I/M" status on various sensor components, I find that
the Catalyst is "not ready" almost continuously since start of this
problem. Sometimes it shows the 02 and HO2 "not ready".
Is there a temperature sensor or some other sensor inside the
catalytic converter?
I've now used about 3/4 of "that" tank of gas, and plan on topping off
at another station shortly and getting under car to check wiring to 02
sensor prior to going to dealer...
I do notice that the converter isn't getting as hot as "normal". I
normally feel floor getting warm on long trips. Part of the
troubleshooting for code "P1151" makes reference to running rich,
trying to make up for a perceived "lean" condition...
Chuck