Why p1157 AF Voltage high after catalytic replacement?
What is your question?
After my catalytic was sawed off by a cat thief I had to replace my catalytic with an aftermarket and with it an aftermarket downstream.
I’ve been getting the AF line voltage high p1157 ever since, any way to fix this?
What makes this problem better or worse?
Spacers on the upstream seem to drop the voltage from 1.4 to 0.9 but when accelerating, the voltage would drop to 0.1 and stabilize at 0.8
How long has your 2003 Honda Element had this problem?
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Compare upstream 02 readings frequency to downstream 02 - if switching simultaneously the cat ain’t working!
This is where the “proper diagnostic equipment” is essential ..
Good luck!
I've seen multiple concerns like this after cats have been stolen on Elements...in Northern California where my dealership is. I can tell you that if the oxygen sensors were damaged or cut, aftermarket sensors are horrible. Also, I've seen them wired in reverse on accident -- pre-cat sensor harness plugged into after-cat harness, and vice versa.
The aftermarket catalytic converters on these vehicles appear to be CARB certified and functional -- it's the wiring and oxygen sensors that get messed up from what I've seen. Go original Honda sensor if an aftermarket has been installed, and ensure the right harness is plugged into the right sensor.
Proper diagnostic equipment will prove what is failing. No other way to accurately diagnose.
Compare upstream 02 readings frequency to downstream 02 - if switching simultaneously the cat ain’t working! This is where the “proper diagnostic equipment” is essential .. Good luck!