OBD reader live data

[Hebz1.6]

Recently had a fairly large drop in my MPG with absolutely no change in my driving habits, car is a Clio mk2 1.6 16v 2002 was previously getting around 40-55mph with sensible driving and even up towards 60mpg on the motorway. Recently over the last month this has dropped down to around 34mpg and no matter how carefully I drive it won't shift (I have reset the on board computer)

Could this possible be pre cat lambda or Map sensor related? Looking into get a wifi OBD reader that connects to my iPhone to read the live data and to see if anything is out of the usual before I spend out on a new lambda and map sensor when it may not even be these two parts?

Was looking at this one here

https://www.ebay.co.uk/itm/291314535194

Just wondering if someone could tell me if it will work on my car (if not what one I would need) and if it would be able to potentially flag up what could be causing it to burn excess fuel.

Also would be of great help if you could recommend the best iPhone apps to show the live data.

Cheers

 

[McGherkin]

I'd go with Pre Cat Lambda. Worth checking, but it's usually that.

Use DashCommand. 'tis the best.

 

[barnesautos]

Recently had a fairly large drop in my MPG with absolutely no change in my driving habits, car is a Clio mk2 1.6 16v 2002 was previously getting around 40-55mph with sensible driving and even up towards 60mpg on the motorway. Recently over the last month this has dropped down to around 34mpg and no matter how carefully I drive it won't shift (I have reset the on board computer)

Could this possible be pre cat lambda or Map sensor related? Looking into get a wifi OBD reader that connects to my iPhone to read the live data and to see if anything is out of the usual before I spend out on a new lambda and map sensor when it may not even be these two parts?

Was looking at this one here

https://www.ebay.co.uk/itm/291314535194

Just wondering if someone could tell me if it will work on my car (if not what one I would need) and if it would be able to potentially flag up what could be causing it to burn excess fuel.

Also would be of great help if you could recommend the best iPhone apps to show the live data.

Cheers

That's the Wifi dongle I use and it works well on other cars , but as my Ph1 is 2000 its functionalities are limited .
It should work with yours ok

 

[Hebz1.6]

Went for the reader and the dash command app plugged it in and got it setup today and got the following readings whilst on a warm idle just wondering if anyone could confirm they're normal as I'm not 100% sure on what I'm looking for

Idle was sitting between 730-780 rpm with the engine vibrating heavily and shuddering the car (has always done this on idle)

Map sensor; 38/41 KPA
O2 sensor; 0.090/0.725 V
MAF; 0.4 lb/min

With just the ignition on the results where as follows

O2 sensor; 0.400 V
MAP; 99 KPA
MAF; 0.3 lb/min

also it come up with this when i went into the diagnostics, both the catalyst monitoring and Oxygen Sensor come up as 'not complete' whilst the rest come up as either complete (green symbol) or not supported (orange symbol) What could this mean is it that the reader can't pick up a signal from the O2 Sensor and the sensor that monitors the catalyst??

Also another thing is the timing of the engine when on idle it gave a reading between -01 and +10 on the chart shown below what does this mean as I've got a feeling the timing is slightly out therefore result in the car feeling abit sluggish and the rough idle??

as you can probably tell I'm completely new to all this so any information of what readings i should be seeing and how to use this app and reader to perform tests to make sure its all running how it should would be greatly appreciated.

Cheers

 

[McGherkin]

Ok, so from the top the idle at 750-800rpm (and a bit rough!) is consistent with a factory mapped car. Most maps up the idle to 900ish rpm because of the roughness.

The incomplete parts are nothing to worry about, it's to do with performing an OBD emissions test and needs the engine hot etc. Forget that bit.

Timing is ignition timing, not cam timing. Ignition timing is computer controlled whereas the cam timing is done by the belts, pulleys and dephaser.

Figures for the O2 sensor at least seem fine.

 

[Hebz1.6]

Ok, so from the top the idle at 750-800rpm (and a bit rough!) is consistent with a factory mapped car. Most maps up the idle to 900ish rpm because of the roughness.

The incomplete parts are nothing to worry about, it's to do with performing an OBD emissions test and needs the engine hot etc. Forget that bit.

Timing is ignition timing, not cam timing. Ignition timing is computer controlled whereas the cam timing is done by the belts, pulleys and dephaser.

Figures for the O2 sensor at least seem fine.

Very helpful reply cheers for that, pretty clever little devices really for the amount they cost! So if everything seems to be 'normal' back to the main reason for all this the drop in mpg is more than likely going to be down to the pre cat lambda you stated before

 

[McGherkin]

I can't remember how much it dropped by, remind me?

It's just occurred to me, colder weather=worse MPG, lol

 

[Hebz1.6]

I can't remember how much it dropped by, remind me?

It's just occurred to me, colder weather=worse MPG, lol

dropped by a fair amount, was getting around 45mpg driving carefully and even close to 60mpg on the motorway now I'm struggling to get 35 driving like a granny

 

[bloke]

you need to look at how the lambda is switching and short term fuel trims.

 

[Hebz1.6]

you need to look at how the lambda is switching and short term fuel trims.

could you explain abit more? completely new to all this sorry

 

[bloke]

have a google, plenty on there explaining it, i'm buggered if i'm typing loads out for you:wink:

 

[Hebz1.6]

have a google, plenty on there explaining it, i'm buggered if i'm typing loads out for you:wink:

Got my head around fuel trims so will have to keep an eye on that tomorrow whilst driving around at work! Haven't had much luck with lambda switching though google search isn't helping me with that one