When your pony won’t gallop on the freeway, you can’t pass the slow horses. SureTrack community member AAMOTORS had a Mustang in their shop that had no power to pass like it was starving for fuel. They posed the question to the community, and with the help of fellow community member DAG1365 and others, they were able to resolve the issue.
The following Real Fix summarizes the interaction between them in the community that led to the solution.
Vehicle
2007 Ford Mustang GT 4.6L
Title
No power to pass, repaired intake manifold leak.
Complaint
Customer complains that car does no have power to pass. Appears to be starving from fuel.
Diagnostic Steps Performed/Parts Replaced
Found codes PO171 and PO174 (System Too Lean, Bank 1 and 2). Fuel filter and fuel pressure check out OK. MAF sensor was found dirty and was working on and off, so we replaced it. Seamed like the problem was fixed, but customer brought the vehicle back a week later with the same complaint.
Best Answer from Community Member DAG1365
If fuel pressure and volume are good, be sure you do not have any vacuum leaks. Smoke test intake and check mass air flow sensor for debris on filament.
Cause
Found an intake leak that we could not find before. We replaced the gasket and it looks like it took care of the problem.
Correction
Replaced intake manifold gasket and vehicle runs properly.