Engine light

[Velociraptor82]

Hey all, Coming home from work the other day i knoticed the engine light on the dash come on. There was no fault displayed on the clusters lcd nor did the car feel any different driving. Temperture stayed the same so I wasn't sure what it was all about.

After getting home I looked up the owners manual which was very helpful by telling me to take my car to the dealer straight away.

I've checked the oil, coolent, belts & water but all seems fine.

Does anyone know what this light means and what else I should be looking for?

[photn]

most cases its a sensor thats either come loose or i damaged.

if you had a Dreamscience, Xcal or bluefin or even a scanguage 2 you would of been able to find the fault.... but probably just easier to take to a dealership.

in my experience its the exhaust manifold oxy sensor.

[DZFord]

My check engine light was on because of the rear 02 sensor after I changed the exhaust. I purchased an OBDII reader / scanner tool off ebay. They're not too expensive, plug straight into the OBDII port (which is near your right knee under the dash), tell you what the error code is and give you the option to clear it, which turns off the CEL.

It will work on any car that is OBDII compliant (our Focus is), and purchasing one is probably cheaper than taking it to the dealership and getting charged for diagnostics.

[spedwards]

I got ScanGaugeII for the express purpose of resetting faults on the ST170. At $45 a pop to go to the mechanic to tell me the code each time the SCII for $190 was a bargain!

The first was malfunction on the post-cat O2 sensor (P0141) which was fixed by a replacement sensor. The IMRC stuck open (P1518 which comes on intermittently and I still have to organise a fix. And then this week I got one for slow response for the pre-car O2 sensor (P0133).

[Velociraptor82]

Thanks for the recomendations guys. I've had my aftermarket exhaust on for almost a year so I don't think it is that causing the problem. I'll have a look for this sensor and replace it in the hopes that it will remove the code. I'd prefer to fix whats causing the code rather than just clear it.

[DZFord]

I just had a thought - replacing the sensor may fix the problem but may not actually turn off the engine light?

Buying a scanguage / OBD sensor isn't just about clearing the code. It will diagnose it too. That way, you might not waste your money fixing something that isn't actually broken.

[Velociraptor82]

Thanks for the info DZ. Strangely enough tho the light went off all by itself and during the week.

I'll still try to pick up sensor anyway to see what it says. however not an urgent thing at the moment as I'm still waiting on my strut to be replaced. Gonna call the repairers tomorrow to find out whats happeneing.

[spedwards]

When I first put mine in to check the codes the mechanic suggested that it might go off by itself and it might just be due to a tank of some dodgy fuel. Unfortunately that wasn't the case in my situation and I was getting P0141 everytime the car was started, but if I was you I wouldn't worry too much unless it comes back again.

I've had P0133 twice now, I'm giving it another time before I go about getting it replaced.

[LaserLikeFocus]

My ECU went belly up after following a semi on the Hume Highway for some distance, and the (orange) engine light came on. Luckily it was only this kind of false alarm.

Is that all it was? Should I be more worried?