LTFT running rich on bank 2 LY7

[tander977]

Holden VE SV6 Ute LY7,
Hi I have been trying to figure out my Autel scan tool under Fuel Trim Data - Long Term Fuel Trim Bank 2 Cruise/ Acceleration being high negative ( around -40% ). Under Engine Data 1 and Oxygen sensor data the LTFT for Cruise are normal. I have taken out injectors and cleaned, not leaking. Replaced upstream and down stream oxygen sensors, used petrol cleaner treatment, tested fuel pressure 60 psi. Read the temperatures at front and back of both catalytic converters, 20 degrees difference ( sure they are flowing ) can’t pin point any exhaust leaks. Taken spark plugs out, one was not tight number 6. Acceleration feels like it lacks sometimes, I have a throttle controller. Reset fuel trims, throttle body relearn, replaced tps and evap solenoid. Had it running for 30 minutes the LTFT went from 50% to 27% then started to go up, then went for a drive around block and they went back up to 47%, it’s not the throttle controller messing the numbers up? Or could it be even a fault with ecu, tried a few scan tools same readings. Would a smoke machine be any help checking for leaks? Any ideas would be appreciated Cheers.

 

[tander977]

Forgot to add replaced intake manifold gaskets as well…

 

[vywgn]

Cat converter is the issue

 

[tander977]

Cat converter is the issue

Thanks the Ute has done 350000km and they do still look like the original cat converters on there.

 

[Xplaya]

Howd you test for leaks? Might be time to use a smoke leak detector to be 100%. Its probably near the cat area making your 02 go outta wack. Whats your STFT reading. What about your 02 readings

 

[tander977]

Howd you test for leaks? Might be time to use a smoke leak detector to be 100%. Its probably near the cat area making your 02 go outta wack. Whats your STFT reading. What about your 02 readings

Tried blocking exhaust though really need to put a smoke machine on it to verify. STFT sits about +6 after 30 minutes of idling. O2 readings are similar all in acceptable range, it’s just the fuel trim data cruise/acceleration LTFT. No engine light/codes yet.