Looking To Buy a Used Fifth Generation Mustang? These Are the Most Common Issues

The fifth-generation Mustang (S197) is a successful reinterpretation of the classic 1960s pony car. Built from September 2004 to June 2014, it brought back the muscle in terms of design and performance becoming very popular among enthusiasts of the nameplate.

If you’re among them and want to buy one, now is the time since they sell for bargain prices. With a little luck and a lot of patience, you can find a well-maintained model for around $15,000, which is almost twice as cheap as a new, current generation entry-level Ecoboost.

However, since we’re talking about a used sports car that has surely seen its fair share of abuse, several issues can occur. Based on feedback from owners and Ford mechanics, we put together a list of the most common five, so make sure to check them out if you intend to spend your money wisely.

Corrosion on the front edge of the hood

This is by far the most common issue and it's often visible only when raising the hood, on its front edge. Many owners have reported that the bubbling starts on the inside and, in time, extends on the outer part of the hood.

It seems the cause is iron contamination during the painting process which explains why the vast majority of S197 owners have encountered it.

In case you find a Mustang you really like, and this is the only problem it has, fixing and repainting the corroded area won’t help in the long run, as it tends to reoccur. Instead, what you should do is replace the hood with an aftermarket version, which might cost somewhere in the $400 region. While this is relatively cheap, painting it will require at least another $1,000.

Seat brackets tend to rust and eventually break

Regardless of the model year, all fifth-generation Mustangs are prone to this annoying problem that damages the brackets that hold the seats in place.

When you’re examining a potential buy, get a flashlight or use your phone and check for any signs of rust. If you see small amounts, you should keep in mind that this problem should be fixed sooner rather than later and it involves taking the seats off, cleaning, rustproofing, and repainting the brackets.

Clogged catalytic converter

Symptoms can vary but usually you will notice a drop in performance, an increase in fuel consumption, and a rotten egg smell coming from the tailpipes. Using a specific cleaner can temporarily alleviate these symptoms but replacing the part is ultimately unavoidable and very expensive.

Our advice is to thoroughly test drive the car before buying it and if you notice any of these signs just walk away. Also, if it’s a high-mileage model, check the maintenance history and if one or both catalytic converters have been replaced, it’s a great sign that it was well-maintained.

Damaged fuel cap gasket

A lid-up check engine light might be a dealbreaker to the vast majority of used car buyers but if it results in a P0456 error code, it can be fixed quickly and cheaply by replacing the gas cap.

The issue is often caused by a worn-out gasket, so don’t run away if the dreaded light comes on during a test drive. Keep your cool, make sure that you or a mechanic runs a diagnostic using a specific tool and if the aforementioned code is the only one that pops up, use the issue to negotiate a better price.

Rough Running Engine

This is another problem that looks far worse than it actually is. If you notice it, keep in mind that the most common cause on all S197 Mustangs is the mass airflow (MAF) sensor, which leads to a check engine light and the P061b error code.

Sometimes, it can be fixed by taking out and cleaning it but for added peace of mind, you should just replace it. An aftermarket MAF sensor will cost around $200 and with a bit of elbow grease, you can replace it yourself.

If the resulting error code is P2103, the culprit is the throttle body, which can also be taken out and thoroughly cleaned. If it needs to be replaced, it will cost you between $200 and $600, depending on the engine and the part’s manufacturer.

Before we conclude, make sure you avoid models built in 2004 since they are plagued by many other issues that have been fixed in newer editions.

Apart from those early units, all fifth-generation Mustangs are pretty reliable and it’s unlikely you’ll encounter any major hidden issues.

Like always, make sure to thoroughly check the vehicle’s maintenance history, and regardless of how well informed you are, always perform a pre-purchase inspection before you seal the deal.