94 F150 351W 5.8L V8 E4OD

I have been dealing with a stumbling engine (sometimes to the point of stalling) at very low throttle/RPMs. The only vacuum leak I have been able to track down is from the throttle body/TPS as seen in the video below. Is that significant enough to cause drivability issues? I also found an exhaust leak essentially at (but slightly downstream) from the O2 sensor as shown in the second video. Significant enough for drivability issues? Let me know what you think.

https://youtube.com/shorts/VV6J_kTY8XI?si=MpCmH-e7E7WhTd9f

https://youtube.com/shorts/PuGPg8r5L5Y?si=wO0nDowVlvXQTB-F

 

Any thoughts?

 

I've never done a smoke test on my truck but my opinion is that those leaks aren't enough to cause idle issues.
I would pull engine codes, then test the TPS and Idle Air Control valve.

 

I have to disagree, smoke the intake and exhaust, perform an O2 reaction test (watch fuel trims and introduce fuel) (propane/brake clean) around intake.

Smoke the exhaust and fix leaks..

 

Looking at your other threads, how did the wiring repair go? Several sensors share common wiring on these trucks. Just wondering if all your sensors are getting proper voltage.

 

I've been chasing this stumbling problem since before the wiring catastrophy. I was able to repair the wires (what appears to be) successfully. I did have to replace the PCM as it had blown some capacitors but the truck is back to running the same as it was prior to the wiring issue.

 

Not to dismiss the smoke around the throttle body, but how are your ground wires from your battery negative to your engine block, frame and/or starter mounting bolt, as well as the ground wires on the upper driver's side of the radiator support?

 

I smoked the intake and exhaust and the results are in the videos in the first post. I've read various posts stating that leakage at the TPS is somewhat common and shouldn't cause drivability issues but wanted other opinions.

I'm not familiar with how to perform an O2 reaction test but I will do some research

 

This is next on my list. Visually they don't look terrible but I'm going to clean them regardless.

 

Fuel pumps are sensitive to voltage issues and the ignition system is grounded through the distributor, to the block, so bad grounds are definitely worth looking into.