Bought a used FR-S but...
 

I purchased a used FR-S two days ago, and while the car is damage free the previous owner installed a few mods on the car (fog lights, exhaust, tints).

The car passed inspection while at the dealership and won't need to be inspected for close to 2 years...

Day one everything is good, but two days off the lot, I got a check engine light which when run through a OBD reader came up with a catalytic converter error... Fast forward another day, and the light is off {going to monitor the fuel gauge closely on way home today}...

I won't even pretend that I'm some sort of car guru - because I'm not (qutte the opposite actually, I'm more of a car N00B looking to learn) - what's my best course of action here?

Should I go back to the stealership and complain (have them check the car)? Should I go to a local mechanic? Am I freaking out over nothing (should I wait a few more days to see if it comes back)?

Thanks in advance for the help... I have a handful of other N00B questions, just have to find the list i jotted down...

Just to rule it out.....Is it still the stock header?

Stock header is this beast
http://www.garagefrs.com/wp-content/...4-1024x675.jpg

An aftermarket header is going to just look like 4 pipes coming off the block
http://www.ft86speedfactory.com/exha...eaders-73.html

EDIT: Just to clarify why I'm asking. The car has 2 catalytic converters stock. One in the header and one in the front pipe. The one in the front pipe does not have any sensors hooked up to it so any fault code related to a cat should be from the cat in the header.

An aftermarket header might have a high-flow cat or no cat and this can throw codes(especially if no cat) if it is just put on the car and not properly accounted for in a tune. If you do still have the stock header then it shouldn't be any problem for the dealership to replace if it is a faulty part.

If it is an aftermarket header then you might be SOL in terms of the dealership fixing it. You could try to purchase a stock header from a member on the forums, have someone swap the stock one onto the car and see if you get codes. If you are still getting codes with a stock header then you probably should take it to the dealership

Check all your paperwork. Let us know what year the car is, and how many miles on the odometer.

Should, most likely still be under the emissions controls warranty at least...then it would go back to a Scion Stealerhip for a check at no charge. If they passed it on smog/safety, surely they're responsible to make it correct.

And keep the Honda as a backup/winter car...though, at 13yo, a Honda has begun to have corrosion related problems...all items under the car...though not the body itself...assuming it's driven in the nasty salt.

Could be a faulty O2 sensor.

Also, does the FRS still have stock muffler attached? Get it checked out from the dealer regardless.

It sounds like the previous owner installed an aftermarket exhaust header that doesn't have a cat. This is a common modification on these cars because it gives a reliable bump in power and usually eliminates the 3-4k torque dip. However, as you have seen, the car will occasionally and randomly throw a CEL because it sees no difference between readings from the front and rear O2 sensors.

There are a few ways to remedy this. First, some people try using a spacer for the rear O2 sensor. This seems to decrease the frequency of the CEL popping up, but is not an ideal solution. Second, you could take the car back to the dealer and demand they put the stock header back on. Technically, the removal of a catalytic converter is against federal law. If you make enough noise and if you get lucky, they might install a stock header for you, which would remedy the CEL.

The third option, though, is a more complicated answer. If you were planning to do performance mods to the car, you might as well keep the header for now. In that case, your best bet is to get your car tuned. An aftermarket tune will usually disable the particular CEL associated with a catless header. By doing this, your OBD2 emissions systems will all report "ready", meaning you can pass an OBD2 emissions inspection.

There are a couple options for tuning. The easiest is an off-the-shelf tune using the OpenFlash Tablet (OFT). Many people on the forums (including me) use the OFT with good results. It's roughly $500 new, but you can sometimes buy a used one for less.

The other main option is to get tuned using ECUtek. This is more expensive and more time-consuming, but it means you can get a tune customized for your car. If you plan on getting a turbo/supercharger down the line, this is your best bet. To go through this route, you'd need to talk to a reputable tuner like Delicious or Moto-East. There are certainly others, but these two are the most popular.


Edit: if you can, take a pic of the header so we can verify. You can easily see it down the front of the passenger side of the engine bay, under the dipstick. If it looks like a bunch of heat shields, then you might have the stock header, and I have no clue why you're getting a CEL. But if you see a set of individual pipes, you probably have an aftermarket header.

If you are in a state, county or city that requires emission testing then I would go back to the dealer that sold you the car and have them check it out. You have not had the car long enough to have to deal with issues yourself. Let them deal with it and possibly save you some money in the future. If the light comes on again then write down the code. If the light is off now and you do not have the code then chances are they are going to say they cannot find any issue with the car.

Thanks for all the responses!

Not sure on the header (will check and get back to everyone)... I should mention that I bought the car off a Nissan dealership who received it as a trade-in I took it to a local Scion dealership who ultimately ran their own OBD got the catalytic converter message and said they couldn't touch anything because of the aftermarket parts (exhaust?) --- I snapped a picture off the OBD I used at autozone which I'll also post later but the # / message per that OBD was as follows:

P0420
Catalyst System Efficiency Below Threshold Bank 1 (Permanent)

As for the the car it is a 2013 FR-S with 34,000 miles.

Will definitely be keeping the Honda and / or driving my dad's spare Corolla when the weather gets too rough (still planning on getting winter tires, and riding this until first snowfall but that's a discussion for another thread!).

almost willing to bet its catless exhause and possibly aftermarket header causing the CEL

In most states these days, a smog check is mandatory upon transfer of ownership of a vehicle.

So it's the responsibility of that Nissan Stealerhship at this point.

They may have smogged it with their own tech, or subcontracted it for the smog.

Either way, if you insist on return of the vehicle to stock, it's certainly the Nissan Stealership in trouble not you...and they should very well know that.

Any problems...see their General Manager or Owner...in person...one on one in a private office. (Forget any talks with their sales or service depts.) A verbal threat of a lawsuit, or written letter stating same works quite well in these cases.

From Google Search:
General Manager (GM) Job Description (includes)

Focusing on any customer complaints that department managers are unable to rectify and taking the necessary steps to resolve these complaints.

Sounds like something VW did with their TDI cars. :D

"Stealerships"
"verbal threats"

Geez. It's a simple fix that the dealership should take care of. But go ahead, antagonize the other party before you even start a business transaction, best way to go about getting "service" for your problem.

-alex

Just get it tuned. You're gonna end up buying exhaust later anyways

This! O2's can go bad if it had crazy mods before.

Even without crazy mods they seem to go bad more often than any other component. Some makes even consider them a "wear" item.