Advice needed please (low idle & hesitating throttle)

[Rattlesnake]

Hi all,
I have owned my 2000 year Yaris VVTI 1.0L for 14, years and absolutely love it. Its been insanely reliable and I have always fully serviced it (filters, plugs, belts etc).
In the last year its developed what I can describe as the below:
1) hesitating / very light spluttering when at idle and trying to pull away. I have to tap the accelerator pedal before I pull away to lift the RPM a bit and then pull off
Something interesting is if I put my foot on the accelerator to rev the car high, the first split second from idle it completely hesitates and splutters. The car idles very low (to the point where on the digital dash display it doesn't show any small lines at the RPM garage (maybe ids at 500rpm..?). I think this low idle has caused a whistle noise from the throttle body area.
2) no warning lights at all and no fault codes
3) I've smoke tested the vacuum system and there are no leaks at all, was kind of hoping it would be a simple pipe leak.
4) I cleaned the throttle body and air mass meter. No change

Genuineky don't know what else to check or change, the spluttering worries me as I feel its causing the engine to work harder.

Any advice will be greatly appreciated, I have searched the forum and the below was the only similar I could find but no real answers in it
https://www.yarisworld.com/forums/showthread.php?t=56269

thanks in advance!

[bronsin]

I take it there are no codes?

[ex-x-fire]

I'd check fuel pressure.

[Rattlesnake]

I take it there are no codes?

None at all :cry:

[Rattlesnake]

I'd check fuel pressure.

Will do, any advice on the dos / don'ts?

[alanwagen]

It probably needs it anyway but get some long q-tips and throttle body cleaner as a dirty throttle body can hurt the idle.

[Rattlesnake]

It probably needs it anyway but get some long q-tips and throttle body cleaner as a dirty throttle body can hurt the idle.

Ok will do

[bairjo]

Listen to this guy.....

http://www.youtube.com/watch?v=3B-a8WJtd8w

[Rattlesnake]

Hi all,
So went to my local garage and he had a good look, he's almost certain its all being caused by a worn out cat' , he feels the whistling is back pressure and when you rev the car hard at idle it smells like worn cat... do you guys think possibly that's the cause? Now to find a cat that isn't £200+ cosindering the car is probably worth that lol!!

[bronsin]

Ask him if he’ll Guarantee when he changes the cat that will solve the problem. I.e. you get your money back if it doesn’t.

Maybe he’s right maybe he’s wrong I don’t know but cover your ass!

[Rattlesnake]

Ask him if he’ll Guarantee when he changes the cat that will solve the problem. I.e. you get your money back if it doesn’t.

Maybe he’s right maybe he’s wrong I don’t know but cover your ass!

Haha good call!! We unplugged the MAF sensor and it drives perfectly, its so weird, I would have thought a cat issue would cause it to drive poorly even without the MAF connected... starting to do my head in :iono::bellyroll:

[bronsin]

My son had a Toyota echo with a code that suggested a map sensor. It turned out my Yaris and his echo had the same sensor. So we swapped them. Now my IRS had a code and the echo didn’t have a code. So it was the sensor

[Rattlesnake]

My son had a Toyota echo with a code that suggested a map sensor. It turned out my Yaris and his echo had the same sensor. So we swapped them. Now my IRS had a code and the echo didn’t have a code. So it was the sensor

The joys of an older car with less sensors or diagnostics capability haha. I have a MAF on order so will try that first. If it doesn't fix it then bite the bullet on a cat :iono:

[Cletus Garfunkle]

Just my .02 you said it ran good with the maf unplugged.
Maybe look at the intake hose after the maf carefully make sure there is no weird cracks or breaks in it. Take it off and shine light through the whole thing and if you can see through I feel like that would be ur problem.
To me it seems like the maf is getting a wrong reading.
I doubt it would be the cat mine has been bad/stinks for about 3 years and I do not have the same problems.
(Also if you want to be really cheap cut the cat off and replace with test pipe/gut the cat. for testing purposes of course.)

[Rattlesnake]

Just my .02 you said it ran good with the maf unplugged.
Maybe look at the intake hose after the maf carefully make sure there is no weird cracks or breaks in it. Take it off and shine light through the whole thing and if you can see through I feel like that would be ur problem.
To me it seems like the maf is getting a wrong reading.
I doubt it would be the cat mine has been bad/stinks for about 3 years and I do not have the same problems.
(Also if you want to be really cheap cut the cat off and replace with test pipe/gut the cat. for testing purposes of course.)

Ok will do mate thank you,l.
Haha yeah I was thinking that for cat but MOTs over here are quite strict ;)