Remote tune lean spot

[Kod3]

Hi All,

I am trying to have my car mapped remotely and my tuner has seen a lean spot during a pull in forscan logs. The car seems to be idling slightly rough and the car is hesitating whilst driving or pulling back power.

I plugged odb2 reader into the car and with forscan notice that 02 sensor bank 1 pre cat (O2S11 in forscan) seems to be reading a high voltage. It starts at about 1.5v and can fluctuate anywhere up to about 3v. Pretty sure this should be reading below 0.9v?

The car is decatted and I have replaced the o2 sensor thinking this was the issue but it still seems to be reading high in forscan. I really am not sure where the issue lies not so any pointers would be very much appreciated.

Thanks.

 

[scooter123]

Ever heard of the Placebo Effect. It's when you see an "improvement" that doesn't exist because you expected an improvement. People remove Cats because they think it will improve exhaust flow and thus increase power. On our cars the Cat has been designed with features that act to create a standing vacuum wave at the outlet for the Turbocharger. This increases the efficiency of the Turbocharger and increases power as a result. From what I've seen you'll get more power from a hybrid turbo with the stock Cat in place than without. It's only when you go to a larger cased turbo when removing the stock Cat will proved a benefit in terms of power. BTW, that necked down area in the Turbo is the trick that Ford uses to increase the turbocharger efficiency. Take a look at a high power 2 stroke engine and you'll see a similar feature, a smaller diameter followed by a much larger volume.

Because of this I recommend that you put your stock Catalytic Converter back on your car.

 

[Kod3]

Thanks for the reply fella. I was contemplating putting back the cat so based on your suggestion I will get it done and hope for an improvement. Much appreciated.

 

[M-Sport fan]

Hell, even the Rally 1 class WRC cars must run a catcon nowadays!