psst: your IMPENDING FIERY DEATH light has just come on

Here's a Bloke Skills-related confession: I am neither especially interested in, nor especially knowledgeable about, cars. Just to be clear, I'm very enthusiastic about the benefits of having one - getting to places outside the normal range of public transport, a mobile lockable storage facility for stuff, emergency rain shelter, all of that, but I don't have particularly strong opinions about brands and models, and I certainly don't have much knowledge about the internal workings of cars beyond being able to change a wheel in an emergency and knowing how to top up the oil and the washer fluid. Oh, and I have changed a fuse a couple of times.

So you might argue that my lack of enthusiasm for deep research into what car would be best to buy back when I was buying a car for the first time is what led me to the safe and unexciting choice of the Ford Focus. To which I would say a) yes, you're probably right, but also b) why would "excitingness" be a criterion anyway? I mean, who cares, really? And there's also c) yeah, but my choice has been borne out as a pretty good one given how little trouble the Focus has been over the five and a half years I've owned it and the getting on for 85,000 miles I've put on the clock.

One of the key considerations when owning a car, particularly one of advancing age (the Focus is about 12 years old now), is making the judgment of when it becomes more trouble than it's worth, i.e. when the niggly maintenance issues that inevitably crop up start costing more to fix than the residual value of the car. While I don't think we've reached that stage yet, it is undoubtedly true that I've had more trouble with the car in 2013 than in the previous four years put together.

The only time the car had broken down before this year was in the depths of winter not long after I'd bought it when a coolant hose froze and cracked on a particularly frosty morning causing the car (ironically) to overheat. The first I knew about it was when the little yellow engine management light came on on the dashboard as I was passing the Severn Bridge toll booths (in the non-paying easterly direction) and the car had a sudden loss of power. A quick tow to a garage from the AA and a new hose and that was sorted.

This year, by contrast, in addition to an MOT bill running to several hundreds of pounds to replace a load of suspension parts, I've had a couple of incidents. Firstly, when on the way from home to the motorway one morning, the yellow engine management light started flickering on and off intermittently, there was a sudden loss of power and the engine started to chug lopsidedly like an old tractor. I managed to limp back home and called out the AA man, who plugged his little diagnostic gizmo into the socket under the dashboard and determined that there was a misfire in one of the cylinders. A new ignition coil pack and some new HT leads sorted that at relatively modest cost, at least until the exact same thing happened a couple of weeks later. I was a bit concerned that this indicated some major problem with the engine management computer, but the AA man assured me that, nah, it was probably just a dodgy ignition coil, replaced it at no charge, and to be fair to him it's been fine since.

Then, a month or so ago, as I was driving back to the office after a lunchtime trip to B&Q, the engine light came on again. A constant light this time, and accompanied by no discernible problem with engine sound or power, but a bit worrying nonetheless. The lack of any obvious problem gave me a bit of a dilemma, though - ignore it for a bit, or take it somewhere and get it diagnosed? A no-brainer, you might think, until you see how much motor maintenance people want to charge you just for plugging in a code reader and reading the results out to you. Halfords Autocentres and Kwik-Fit both wanted about 40 quid, and while I daresay there might be an independent who'd do it a bit cheaper it still seemed a bit of a wedge for 2 minutes work. So I decided to take a punt on buying a diagnostic scanner gizmo off the internet, as they're readily available on Amazon, and as it happened this one was available for a mere 13 quid. Obviously I was also taking a punt on the engine not eating itself while I waited for it to arrive, but luckily I got away with it.

So anyway, when I plugged the unit in (having located the port under the steering wheel and located a suitable flat-bladed screwdriver to remove the cover) it told me that there was a single fault logged on the computer, specifically code 0420, which translates as Catalyst System Efficiency Below Threshold (Bank 1), which further translates as, basically, your catalytic converter isn't operating at maximum efficiency. To which, after 12 years and over 140,000 miles, I say both meh and also no shit, Sherlock. Most of the sites which give you more detail about these codes do also specifically say that a cylinder misfire can cause some damage to a catalytic converter owing to the unburnt fuel that then ends up in it, so that makes sense I suppose. I'll keep an eye on it, but since I'm not currently experiencing any obvious loss of power or difference in fuel consumption you'll excuse me if I'm not rushing off to throw money at the problem.

All of that extremely lengthy preamble brings me to my point, though, which is this: in these days when we can put a man on the moon and work out the most complex hire purchase agreements it really ought to be obligatory for cars to display a bit more helpful diagnostic information in the event of the computer detecting a problem - at the very least the diagnostic fault code (or codes), but preferably a bit of explanatory text as well. I'm delighted that we've come as far as having an international standard for the codes, but there's absolutely no reason why the engine computer, having detected and logged a fault, should then say to you: something's wro-ong! but, hey, I'm not going to tell you what it is, because IT'S A SECRET, HAHAHAHAHAHAHA! As an aside, the only general rule I've been able to glean off the internet is that, in the absence of an indication of what the fault code is, in general a flashing engine management light is more serious than a constant one.

The good people at American motoring website Jalopnik have decided that they agree with me, and, additionally, that they're mad as hell and they're not going to take it any more. As one of the commenters very eloquently puts it:

you need to have some way of differentiating "screw the gas cap back in, idiot" from "pull the hell over: impending fiery death"

So in addition to a couple of pithy articles on the subject they've created an actual White House petition to get some form of automatic decoded OBD display mandated on all new cars. The petition seems to be inaccessible now, though - you just get redirected to the petitions home page instead. So I expect that means it'll be getting passed into law any day now, or something.