Check Engine

[jackw_77]

Happy New Year everyone!

Just to share my traumatic experience so you can bear my pain as well:

Late in the evening the other day I was on the A12 doing 70 or so, and suddenly the Check Engine light just came on. There was a quarter of the tank left when it all happened. There was still some 15 miles or so to go but I got home safely, without any problems or loss of power. I managed to book a visit to Lookers in Chelmsford on the 31st of December. Drove the car there - with the light on, dropped the car and went home in a little Yaris. Got the phone call about an hour later: there were two error codes, both related to oxygen sensor. They asked me if perhaps I ran out of fuel - I didn't, or if I filled in with some cheap dodgy fuel - I didn't as I always use BP or Shell. They reset the codes and everything's fine - well not much driving since then though, so we shall see.

Here's hoping that it won't happen again.

So, a mystery...

[Grumpy Cabbie]

From what I have seen on the US forums one of many causes could be the fuel filler cap being open or tampered with.

Why or how this happens is unknown to me and it might not apply to UK spec cars. I know it's vague, but it might be worth looking at next time? Had you just filled up? Had you washed the car or do you not turn the cap until it clicks?

[jackw_77]

Hey Grumpy,

Thank you for your suggestions.

I did wash the car but cannot remember if it was on the very day the light came on or before. I don't think that the cap was loose but of course I cannot be sure. It is not loose now, as I actually filled up on my way home after they reset the codes.

I am about to start a 70 miles journey - let us see what happens.

The whole affair is upsetting - I mean all that technology and we can not even be kept safe from those oxygen sensor codes popping up...

[jackw_77]

AN UPDATE:

Just got back from a little trip. The [censored] light back on after only 50 miles!

This is really, really frustrating - what happened to that legendary "Made in Japan" quality?

[Grumpy Cabbie]

Hmmm, odd one. Have you filled up since the last time - and I mean fill it up full. I'm wondering if it might be water in the petrol? With all the cold weather you could have condensation in either your fuel tank (esp if the fuel cap wasn't tight shut) or the garage might have a water in the fuel issue. A lot are changing to 10% ethanol which can cause problems with water absorption. If they have run their petrol tanks low, this along with cold weather and more ethanol can cause condesation issues and then problems with your car.

There was a petrol garage round here which had this sort of problem. All the cabbies in town avoided it and every now and then one would get caught out and end up with water in his petrol. I was at the local servicing garage when one came in with this very problem having just filled up at the dodgy petrol garage. They emptied a sample form his petrol tank and sure enough there were a lot of droplets of water at the bottom.

You might have another issue and I'm sure others will be happy to offer their comments, but I'd consider some of that stuff you can get at Halfords that absorbs it and burns it through. Might be best to fully fill the tank from another garage first too.

Good luck.

[jackw_77]

Yes sir, I did fill up full. Well, actually it's the same BP petrol station I use over and over again, so by your reasoning - we might be onto something here.

But surely (don't call me Shirley) water filter is supposed to deal with any water in the petrol? Or if not then why would it matter more in our cars than other regular cars?

What is that you mention that I should get from Halfords? Is that some petrol additive?

Anyway - now I have to book another visit and waste time. I am soooooo p****d off.

update:

I just realised that I washed the car before filling it up.

[Grumpy Cabbie]

I might be completely wrong! There is a petrol additive that soaks up any water in your fuel. Might be worth a go.

I'd be very surprised if there was a fault with your car already - though it's not impossible. It might be worth the petrol additive and also turn the fuel cap til it clicks in future. I would also add that I wouldn't suggest you put any additives in the car until you have checked with your dealers first for warranty reasons. Toyota dealers are usually pretty good so have a word with them in that you fear it could be water and see what they suggest?

If they say they'll add the additive themselves then you're ok and it's cheaper than removing the fuel lines etc. I was also hoping others might have some ideas too.

[jackw_77]

This is my fourth Toyota but a first car from new, so naturally I take it all very, very seriously. Probably too seriously.

I'll do just what you suggested - I shall tell them about water and ask about the additive. Thank you!

[kithmo]

I may be wrong here but I was under the impression that the additive that absorbs water is a methanol based product (methanol absorbs water), so if the E10 is the problem then adding methanol will make it worse.

Also there is no "water filter" in a petrol engined vehicle, it's a fuel filter that filters out dirt and debris, water goes right through it. On a diesel engine, the fuel filter is the same, it filters out dirt etc. but not water, but it is situated in a position where the water collects in the bottom of the filter away from the pick up tube inside and the filter is drained/changed before it fills with water.

[jackw_77]

Well, I booked another visit next week, when they will just replace the sensor. It will be interesting to see if the error codes return after that (after all the tank is full of supposedly dodgy petrol, right?).

I thought that those filters are supposed to "catch" water droplets as well, so thank you for the explanation about the filters - that somewhat changes my whole perception of the problem.