Recently I popped two SES codes, a P0172-Fuel Trim Bank One Condition
and a P0420-Catalyst Effeciency Low-Bank one.
I know that the P0420 is a common code to pull with a High flow cat, which I do have.(ZZP 3" DP with highflow cat)
But I'm not sure what the P0172 code would be, from what I've read it seems to be subject to:Fuel injectors or O2 sensors.
After looking around, my thoughts are that, because the Cat. is high flow, it's not reducing the emissions as much as the PCM(stock) is set to accept. Because of that, the rear 02 sensor is reading a rich condition setting the lights.
Again I'm not too sure if that's the case, just seems it could very well be.
Any input would be great.
History:
The Cat is about 6months old, same as the downstream O2sensor.
The Upstream O2 sensor is about 1.5 years old.
These codes only came up after I installed a 3.4" modular pulley this winter, but I drove the car over 2000miles before a light came on after the pulley swap.
My injectors are rather noisy, but I have cleaned them (this summer.)
Fuel pressure is fine, and theres no smell of raw gas, and the exhaust doesn't smell rich, just some residue on the tips.
