Hesitation full throttle >2.5k

[Wellbs]

Ht lead failed last week so replaced with genuine part, still wasn’t right so plugged it into a snapon reader which showed no faults (also no lights on dash) but the pre cat o2 sensor was going wild ranging from 50 to 750 whereas the postcat was only varying by ten points. Changed o2 sensor and serviced the car at the same time with new (correct laser NGK plugs), oil and filter all oem.
Not right still and now have EML light on with hesitation > 2.5k on full or nearly full throttle while in neutral on the drive.
Changed the coilpack for a spare I had at home not made a difference.

My only idea is that the rs tuner map it has can’t keep up with the new fatty induction I fitted and the decat combined.

I am taking it to be mapped hopefully at EFI when I get the time from work but before I go I want to make sure it’s not something stupid.

Cheers in advance

Jack

 

[Daz...]

I put the 98Ron map on mine and ran it with an induction kit and decat with no issues.

Did you change all of the ht leads or just one?

 

[Brigsy]

Pre cat o2 sensor does go up and down the voltage, so might have been ok.. Scan it with clip and find out what faults are stored before firing the parts cannon at it mate.

 

[Adey.]

 

[Wellbs]

Hmm.

I changed all the leads which was the only thing I bought in all fairness i had everything else as spares/service kit.

It was running great for approx a month until the lead went ?