AEM Wideband reading lean under WOT

My wideband readings are

14.7 at idle

13-14 under partial throttle

12.8 down to 11.9 at the redline under WOT

Here is a pic of my tail pipe, I am running standard ECU, standard boost, walbro fuel pump.

I suspect my wideband sensor is not reading correctly under WOT but seems ok under other conditions, I have taken it out and done the check with brake cleaner going to fully rich then to fully lean and all is ok there.

Just after some second opinions everything else seems fine no stuttering or misfires, steady idle at 900??

could possibly be timings out a little I would advise checking it and making sure its between 18-20 degrees btdc

I take it your using vpower and not lower octane fuel?

Yes Bob timing set at 20 degrees and always been run on shell vpower

I have checked all the normal stuff TPS, dizzy, MAF, plugs, leads, injectors etc and all are fine as per the Service Manual so I think I am chasing a dodgy wideband sensor rather than anything wrong with the car it pops and bangs on gear changes and on the over run?

Here's a pic of the plugs?

plugs look spot on to me so don't think you have anything to worry about there
as you say it could possibly be sensors not reading quite right but its not really that lean anyway if its low 11s and your plug condition is backing that up

got me a bit woried im sure the guy that adjusted my timing said he done it to 12 :S

Can you not check it with a timing light mate ?

i dont have one of those wouldnt something happen if timing was out that much? sorry for hijacking thread lol

I reckon that far out it would run like shit ...lol .... timing light are not expensive to buy and very easy to use and a good way of checking it .

yeah think ill grab one car runs great so maybe i got it wrong

Yeah mate it connects to the battery and a lead clips on the no1 spark plug lead  so no difficult scratching your head moments lol .....

Does the AEM allow re-calibrate sensor to air? I used to do this with my Innovate every now and then. ..

bfc10 wrote:
12.8 down to 11.9 at the redline under WOT

Your fueling is spot on?? Should be looking at somewhere between 11.8 - 12.0 WOT top end and your bang in the middle.

Some mappers map down to 11.5 which is conservative but allows a safety margin, but if you're running a wideband set-up you can see what's going on and can physically see if something goes faulty.

One thing to remember with the aem's is that you must let it warm up before starting the car (20 seconds I think) otherwise it can start to clog up and give odd readings. I've had mine for 5 years + and never had a single problem with it, and when checked against others has been spot on.

I know they are calibrated from the factory as there's something on the back for adjustment but I don't think you are meant to tamper with it after that.

Cheers, Ben.

GTI-R US wrote:plugs look spot on to me so don't think you have anything to worry about there
as you say it could possibly be sensors not reading quite right but its not really that lean anyway if its low 11s and your plug condition is backing that up

Cheers Bob, that puts my mind at ease.

Digitalfaze wrote:got me a bit woried im sure the guy that adjusted my timing said he done it to 12 :S

If you look at the dizzy where it is bolted to the top bracket then if it's roughly in the middle (so you have an equal gap each side) that is around the 20 degree mark, hope that helps until you get a timing light?

r called jay wrote:

bfc10 wrote:
12.8 down to 11.9 at the redline under WOT

Your fueling is spot on?? Should be looking at somewhere between 11.8 - 12.0 WOT top end and your bang in the middle.

Some mappers map down to 11.5 which is conservative but allows a safety margin, but if you're running a wideband set-up you can see what's going on and can physically see if something goes faulty.

One thing to remember with the aem's is that you must let it warm up before starting the car (20 seconds I think) otherwise it can start to clog up and give odd readings. I've had mine for 5 years + and never had a single problem with it, and when checked against others has been spot on.

I know they are calibrated from the factory as there's something on the back for adjustment but I don't think you are meant to tamper with it after that.

Cheers, Ben.

Thanks Ben, that's interesting to know as all the info I have read on the tinternet all say low 11's down into the 10's as perfect afrs.

I have cleaned the sensor so will ensure I warm it up before starting as well.

Cheers

Spike