Question About Some Fault Codes Check Engine Light Please HELP

I just purchased a 1996 Ford Mustang Cobra last night, and today the check engine light came on. The car has 96434 miles on it. I checked it with a OBD II Scan tool and this is what I got


PO171 System Too Lean -Bank No. 1
PO184 System Too Lean-Bank No. 2

I cleared the code with my scanner and went to take the SMOG test. The car passed the SMOG fine, but failed the engine computer check. After driving another 30 miles the Check Engine Light Came Back On.

Does anyone know what could be the cause of the car running too lean. I know this is not a good thing as it can blow the motor. This is my first American Car, so I have no clue about what could be causing this. Any help or insight as the what would cause those error codes would be Great. TIA

Also what is the general cost on rebuilding this engine. I want to supercharger the car, but I want to make sure the motor can handle it first.

Problem #2
When I shift from 1st to 2nd or 2nd to 3rd sometimes the tranny grinds even with my foot fully depressing the clutch. Does this sound like the syncros are bad, or is this common with the Cobras?

svttech76 said:

the most common cause of the lean bank 1 + 2 codes is a vacumm leak, check all your vac lines and connections and check your intake inlet tube after the maf for anything that can cause unmetered air to enter the intake.

Intake gasket leaks are rare on a 4v or any modular for that matter so I would check there first.

as far as the trans problem this is probally related to the clutch cable being too loose. The stock quadrant tends to allow too much slack and this causes you to not have enough of a air gap even with the pedal fully depressed for clean upshifts. This can be fixed one of two ways..

1. adjust the stock quadrant, first try the self adjusting method by pulling up firmly on the clutch pedal. if that don't work you can manualy tighten it.

2. buy a aftermarket quadrant and firewall adjuster ( this is what I did)

Click to expand...

Thank you so much. Let me try those two first. Do you think the grinding with the clutch fully depressed could be related to bad sychrons in the tranny. I had that problem on my Audi S4 before.