P.S. Check out the FAQ at the top of the UK forum, it's full of useful information and I'm certain there is a section in it about hesitation/kangarooing etc.

Bear in mind though that these cars do kangaroo a little bit as they are prone to heatsoak, you just get used to it and compensate with a bit more throttle/clutch control.

 

Po434 is the cell code I believe

 

"Heated Catalyst Temperature Below Threshold"

I expect that could be coming from the secondary O2 sensor (the one in the cat).

When you had the de-cat did you use an anti-fowl plug to move the sensor out of the direct gas flow?

 

There was an anti fowl plug present when taking the decat out. The problem still persists despite having an oem cat in place again. I'm considering that once I solve the issue that the cell light is highlighting it should correct the kangerooing issue....

 

You have 2x 02 sensors. 1 in the manifold and 1 in the cat.

The manifold one can cause idle / fuelling issues if it dies.

The one in the cat is just a reference sensor and has no fuel control so cannot cause any issues. It's there to check the efficiency of the cat.

I don't know which of your sensors is a problem but get them both tested.

The CEL code you are getting means the cat one is reading lean / low voltage.

May be that you haven't spaced it out correctly, the sensor is dead or the primary one is reading lean. Or both dead! Testing will tell you.

 

Awesome thanks mate. How do I test them?

 

My guess is primary sensor. If the car has had a decat and its over fuelled at any point it could easily have knackered the sensor up. That'll cause the car to run lean, not feel like its giving full throttle when you foot is to the floor and also cause rough running and kangarooing too. If it was the secondary sensor it'll just throw the CEL to tell you the CAT isn't working as that's its only purpose.

I had this issue on a car once and as soon as it was changed it was sorted.

 

Nackered sensor will not cause the car to run lean, quite the opposite! Damaged 02 gives a lean / low voltage signal, which the ECU sees and of course adds more fuel to try and make it richer. This is part of the reason it runs badly.

Also the 02 sensor is not used when you have your foot down, it runs open loop fuelling then and 02 becomes passive.

 

So
.......I'm going with the primary or secondary sensor? Ignoring the map whacking etc. ?

 

Primary, and yes I'd ignore the map whack for now, best to check things one at the time otherwise you still won't know what the problem is and what fixed it.