I have an 05 f150 with the 5.4 engine. I replaced my cats with magnaflo high flow cats, replaced all the my o2 sensors and monitors with brand new ones. I still get a check engine light saying my sensors are reading bad. My question is, does anyone have any info on the o2 sensor simulators, what part numbers I need for my truck, and where I can order them. My state does not require inspections so that's not an issue to me. Thank you for the help.

 

Best way I have found. Still working for me.

https://www.f150online.com/forums/exhaust-intake-systems/495993-did-non-fouler-o2-mod-twist.html

 

This! But to the rear O2s only. Not the front

 

Why not the front?

 

Front adjust your A/F ratio. Altering the exhaust flow to the fronts will cause them to read wrong and throw your A/F ratio out if wack

 

What exact numerical codes are you getting? If P0420 and/or P0430, that mod to the REAR sensors should take care of it.