I have had poor fuel economy, sluggish performance, slight pinking sound when at full throttle between 1-2k rpm (only using normal octane fuel, does not seem to do it with 97-99 ron)
Had MIL light come on with 0174 lean on bank 1 and lean on bank 2.
I have collected live data at rest and at 2500 rpm...anyone technical enough to look at the long and short term fuel trims to give me an idea if it could be a vacuum or fuel delivery issue?

Thanks in advance

Adam

 

At a first glance I would say MAF signal is too low.
Maybe the MAF itself or some form of air leak behind the MAF.

 

Hi, thanks for your reply. My maf is fairly new and I have cleaned it recently. It seems to respond when at 2500rpm. What should it be at?

Thanks in advance

 

What car is this? And did you replace the MAF with an OEM one or aftermarket?

 

It's an ST220 and I'm not sure if the MAF is genuine or not, I've only had the car about a month now but it looks new?

 

If the MAF looks new, then why clean it at all?
What did you use to clean it with?

 

Also can you take a screen shot when the MIL light is on, all your pics are with the MIL off and a sensor etc could be intermittent.

Rob,

 

if its an st220 its almost guaranteed to be an air leak they are very common i would check all the breathers below throttle body and under inlet manifold

 

This is a pic with light on. Only have one when at idle

 

I would strongly suggest to stop driving the vehicle.
Otherwise your at risk of damaging the expensive cats and possibly the exhaust valves also.
If you used brake cleaner on the MAF, buy a new genuine MAF.
Otherwise check the numbers and make sure the MAF is genuine. When not buy a genuine.

 

I would have expected the MAF readings to change a little but it has not changed at all from 3.3 g/s. As botters says I would suspect an air leak. If not then I would suspect the maf however Bank1 lambda voltage seems to spend a lot of time at 0V!

Airleak post MAF
Bad MAF
Faulty lambda

Good luck

Rob,

 

Thanks Rob,

I am not a qualified mechanic however i did think that it seemed odd that the voltage stayed at 0 for a few of the screenshots.
I always let the car warm up to temp before any form of hard acceleration.....however i have noticed that if i do accelerate when cold ( just to see if its any different) it feels far more lively low down ( havent taken it fully up the revs) when cold. Could this mean its something that is not leaking when cold but when hot, expanding and leaking? My rocker cover appears to be leaking a little on the rear of the engine, front seems fine, could this be a cause?
For the previous post... I used EGR/MAF cleaner to clean the MAF, not break cleaner.
I have bought some carb cleaner today, will have a spray around the engine bay on Saturday when i start it from cold and when its warmed up to see if i can find a leak. Where is bank 1 lambda? Is it on the exhaust manifold at the front of the engine and as i have 3 readings on my delphi software does it mean i have e sensors?
I did 130 miles today and the car sounds lime its running really rich. Under hard acceleration it sounds very induction(y) but not much performance? Also the pinking noise is intermittent and does not do it when cold which makes me think its a vaccum leak and not a fueling/spark issue?? Bloody Fords....love it every time i drive it but gggrrrrr!!!