4.7 stroker running very lean

[Cody Brought]

Hello everyone, I recently got my 4.7 stroker build running, but it is very low on power and occasionally misfires and pops.

I installed an afr gauge: on startup it gives me 14.7:1, but very rapidly increases past 18:1, which is the max reading, before not giving me a reading, only occasionally dipping below 17 while driving. No matter the rpm, the ratio stays very lean.

I got an engine code for high voltage bank 1 sensor 1, but after replacing the sensor and ensuring its connected, the issue hasnt been resolved.

Im running a comp cam 68-232-4
8.5 dcr at .036 quench
24 lb injectors

I checked visually for vacuum leaks and couldnt find any, but will spray starter fluid on the intake while its running when im back home to double check. Im stumped so im looking to the hive mind for help.

Thank you all!

[Gorilla]

What vehicle is it in?

An issue at the fuel pump resulting in low pressure?

A small exhaust leak is possible. Depending on the wideband position it could be throwing it off without causing it to run too rough.

You could also have a leak in the throttle body shaft, IAC, various vacuum lines. All the rubber bits are getting old.

[Cody Brought]

Embarrassingly enough, I resolved the issue by replacing the bank 1 sensor and the wideband. My first attempt at the stroker blew a headgasket and dumped water all over them, im suspecting that ruined them both.

Should I delete this forum, im not familiar with ettiquete. Thank you for the help Gorilla

[mpgMike]

Engine coolant KILLS O2 sensors in short order. Glad you found it.