Check engine light problem

Dope 97GT · Jul 6, 2006

I have a 97GT that has a check engine light on and has been on for a very long time. I have posted a previous thread on this but i but down the wrong codes because autozone doesnt know what they are doing.

These are the 2 codes that are being thrown.
P0172 System Too Rich - Bank No. 1
P0175 System Too Rich - Bank No. 2

So far for maintenance I have changed the plugs and wires fuel filter and 2 or the front O2 sensors.

my sig has all my mods

why is my sig not in here?

1997 Mustang GT 5-sp
mods:
FRPP Bullitt style intake manifold
Msd Dis 4, UD pulleys, 4:10s,
31 Spline Axels, UCAs LCAs,
UPR subframe connectors,
Timing adjuster, O/R BBK H w/MILs,
Flowmaster Dumps, BBK FPR,
Taylor 409 wires, NGK TR55IX plugs,
NOS 255lph Fuel pump, Intrax springs.
C&L 80mm Mass Air Kit, Pro 5.0 shifter

Mike97gt · Jul 6, 2006

I would start by cleaning your maf sensor and go from there.

How does the car run? does it misfire at all?

Dope 97GT · Jul 6, 2006

no misfire runs great i cleaned the maf sensor the light goes off for 40 miles and then comes on. It was hesitating a bit into each gear but it kinda stopped doing that but does it every once in a while.

Also I have a computer from ford racing as well i dont know what it does but it was in the car when i bought it.

I am trying to sell the car and the light is on so its kinda hard to do.

But dont worry ill be moving into a newer mustang

CanadaStang · Jul 7, 2006

If your long term fuel trims are at +25% then that can mean its adding fuel to compensate for added air coming from somewhere, so check for leaks between the maf and the TB.
One thing to keep in mind is that not only will intake leaks (extra, unmetered air) cause this, but also exhaust leaks can too as it will throw the reading off to the 02's and usually cause a rich condition.

-25% would be the pcm pulling fuel out to compensate for rich condition

A dirty Maf sensor usually skews the reading to the pc by telling it there is very little air coming in and therefore it would pull fuel out causing a lean condition, rather than rich.

Pennywise2 · Jul 7, 2006

Dope 97GT said:
no misfire runs great i cleaned the maf sensor the light goes off for 40 miles and then comes on. It was hesitating a bit into each gear but it kinda stopped doing that but does it every once in a while.

Also I have a computer from ford racing as well i dont know what it does but it was in the car when i bought it.

I am trying to sell the car and the light is on so its kinda hard to do.

But dont worry ill be moving into a newer mustang

Yes, fix that check engine light before you sell your car.
I think it's possible you could be running on a rich condition?

Mike97gt · Jul 7, 2006

he has rich codes so it's -25

if you already cleaned the maf, then you might need a new MAF..

One last thing to check before you buy a maf is your fuel presure. get a guage on it and make sure your regulator is working ok. if you have like 100 PSI of fuel presure then you know why your rich as hell

If the FPR is ok then I would get a new maf.

Dope 97GT · Jul 7, 2006

I have a Fuel Pressure gauge and it reads 37-38 psi at idle and about 43-45 at WOT when i had a vortech supercharger kit for a couple weeks i tried to put the lightning Mass air kit on it filter MAF meter and everything that was brand new not sure if that would help but the light came on 40 miles later again.

I got it to pass inspection because of the 4 readings that the computer needs to reset before the light comes back on NY allows there to be 3 ready and you can pass inspection so we drove around with the scanner on until only the catylac one was not ready and it passed then...but right after the light came back on.

I also tried to lean it out by dropping the fuel pressure with the gauge and the regulator and that didnt work so thats why i thought it might be the aftermarket computer I have.

CanadaStang · Jul 7, 2006

svttech76 said:
he has rich codes so it's -25

if you already cleaned the maf, then you might need a new MAF..

One last thing to check before you buy a maf is your fuel presure. get a guage on it and make sure your regulator is working ok. if you have like 100 PSI of fuel presure then you know why your rich as hell

If the FPR is ok then I would get a new maf.

What I was meaning in my previous post was that a good place to start would be to check what the fuel trim's are, as they may give some idea as to what is going on being that there are several mods done to the car. Sorry, I'll have to work on wording things so what I'm trying to say actually makes sense

How long has the cel light has been on? Has it been on since you bought the car, or did it come on after?

Dope 97GT · Jul 7, 2006

CanadaStang said:
What I was meaning in my previous post was that a good place to start would be to check what the fuel trim's are, as they may give some idea as to what is going on being that there are several mods done to the car. Sorry, I'll have to work on wording things so what I'm trying to say actually makes sense

How long has the cel light has been on? Has it been on since you bought the car, or did it come on after?

it came on after i bought it but apparently the battery was unhooked when i picked it up so it was off for a little while

CanadaStang · Jul 7, 2006

Dope 97GT said:
it came on after i bought it but apparently the battery was unhooked when i picked it up so it was off for a little while

Hmmm..... if your maf sensor looks OK and everything else checks out, it might not be a bad idea to take in for a dyno tune as they may be able to fix your a/f if it's something pertaining to the current tune or pcm.

Mike97gt · Jul 7, 2006

CanadaStang said:
What I was meaning in my previous post was that a good place to start would be to check what the fuel trim's are, as they may give some idea as to what is going on being that there are several mods done to the car. Sorry, I'll have to work on wording things so what I'm trying to say actually makes sense

How long has the cel light has been on? Has it been on since you bought the car, or did it come on after?

Yeah it would not be a bad idea to see what the trims are now.

well If the MAF is new and the fuel presure is fine then there is a few more things that can cause this.

1. larger injectors were swaped in and PCM not reprogrammed.

2. 2 or more injectors leaking.

3. bad PCM, or maf signal wirring to the PCM damaged ( unlikely)

Dope 97GT · Jul 7, 2006

i dont know what it could be i dont think it has different injectors but how could i tell?

also i was thinking of buying a stock computer and putting that in then getting a dyno tune and see what it does.

BTW with my car and mods what should the A/F ratio be at?

could a ford dealer do anything to help me?

Dope 97GT · Jul 7, 2006

anybody have any more suggestions and how do i telll the fuel trim?

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