markforrester99

The AFR will change depending on weather conditions but it shouldn't changed massively. If mid trackday you suddenly started noticing it was running leaner then it could point to many things. Fuel pump dying, injector failing or the wideband sensor going wrong. I think if your boosted then its essential.

I wouldn't expected to plug the laptop in mid trackday unless you were using the tracktime as a mapping session. If you started adding fuel to the map and it was pump failure or injector problems then it would be a bandaid fix.

It would be a good idea to do datalogs during trackdays to check for knock, coolant temps, inlet temps etc. whilst on track. Its easily done with say the AEM and could highlight an issue you haven't noticed.

CynicG

Thanks Mark. I do need to get the Win 10 drivers for the AEMTuner. Might do that this weekend. Does the AEM just log data that you can extract after a session, or does it need to be actively connected to the software to capture? Sorry, I really should rtfm!

Define198

mot runs out on 30th, I'm fretting about emissions, i am hoping i would be able to just remove my decat and put a oem cat on to get through, but got a feeling it will still fail. on top of that took it to a garage saturday and they could not even get it on the ramp due to the j's splitter sticking so far out, i have made the car higher as much as i can, but no idea if it will be enough lol

markforrester99

Very little chance of you passing emissions with the cat fitted without having a laptop and messing with some bits on the map to get it to where it needs to be.

Define198

well i am screwed then lol

johnckeen

A lot of people have said they have passed with a cat put back on.
Your map though Define is very rich if I'm honest with all those flames and melting the wide band. By the way your car will not be getting any feedback from the wideband sensor so not a great idea to drive the car until you have a new one.

Shop around and see if you can find a garage that will "help you out" with an MOT

har-vey

My car only ever flames when I use the two step but that's very rare as I kinda feel like it hurts the car.

Define198

my car will only flame when i want it to, e.g when i rev the car come off the gas and then straight back on again at idle, or when i try and down shift rev match clutch in blip the throttle and change gear.

at cruising my afr was always spot on according to my wide band at around 14, normal idle at fully warm was around 13.7? or thereabouts.

what confuses me if you have feedback on and put a standard cat back on, obviously the wideband will not be reading what it should be due to the gasses passing through the cat to clean them up before they get to wideband sensor?

johnckeen

mine idle at warm is 15 and crusing is around 14.5

Yours is definitely running richer than mine by the looks of it, no idea if this is a bad thing!

markforrester99

Wideband should be precat to give you the best reading. 13.7 at idle is rich. Just to give you an idea a NA car flatout at 9000rpm should be around 13.